Yajna (यज्ञः)

Yajna (Samskrit : यज्ञः) or Vedic ritual is one of the distinguishing features of vaidika and laukika karmas. It occupies a very important place in Bharatiya samskriti, literature and way of life.

Development of Yajnas

Our knowledge of vedic rituals is derived with a varying degree of accuracy from the three sources : the Samhitas, the Brahmanas, and Shrauta and Grhya Sutras. The earliest reference to vedic rituals is found in the Rigveda Samhita. While names such as yupa, idhma, drona, darvi, juhu of different things of Yajnas find a mention in Rigveda, a large number of mantras do not have any role in procedures of Yajnas. Similarly, Atharvaveda samhita, which contains popular spells, has no practical use in shrauta karmas. But the case of Yajurveda and Samaveda samhitas is quite different. One can clearly see the ritualistic orientation in the very arrangement of these samhitas. The Yajurveda samhita preserved in two shakas - shukla and krishna, reveal their usage in ceremonial purpose, with mantras borrowed from Rigveda samhita. In their application to the rituals these mantras underwent a significant change, where the system of accentuation of the Rigveda mantras is lost in entirety and "ekashruti" or monotone was adopted. The Samaveda samhita is also a liturgical collection, a copy of Rigveda samhita. The Samaveda samhita has been assigned to Udgatr priests who chant the stotras set to a melody chiefly during Somayaga. They have no other role in yajna apart from chanting the stotras. While the Adhvaryu priests have discarded the accents, Udgatr priests adopt a peculiar fashion of recitation with repetitions and interpolations. Over a long period the transformation of the Yajnas continued with the change in society itself. The main purpose of the Brahmana texts was to describe the procedures for Yajnas in detail, set the rules for the performance, and provide a rationale for their conduct, however they are not clearly organized making it difficult to follow them.

To remedy this a systematic and business-like code was called for, and this led to the composition of Shrautasutras. The sutras presuppose the Samhitas and Brahmanas but unlike them, they give a succinct systemic account of the Yajnas. Thus, Sutras assumed greater importance over a period of time as they formed the bridge between Brahmanas and the changing society. The Shrautasutra is a functional manual of the priests and it follows faithfully its own Brahmana. As a manual it has taken only those terms of the Brahmana which are essential in the operation of a Yajna.

The Grhya yajnas (domestic rites) are as old as the Shrauta yajnas and they have a common origin. The Shrauta yajnas were known by revelation (Shruti) in contrast to the domestic rites which was derived from memory (Smriti). In manner and form the Grhyasutras depend on and presuppose their respective Shrauta sutras, thus indirectly related to the Brahmanas. The Grhyasutras are less rigid than the Shrautasutras and contain less technical terms. Like the Shrauta karmas the grhyakarmas also underwent many stages of transformation. Many of the Rigveda mantras used in domestic ceremonies have become symbolic with no bearing on the ceremonies. The mantras which accompany the wedding and funeral ritesare found in the 10 Mandala of Rigveda, which many scholars believe to have a late origin. On the other hand, Atharvaveda samhita is one of the main sources of mantras for many domestic rites.

A deep study of yajnas (shrauta and smartha) is quite essential for the proper understanding of the vedic literature, the development and stratification of the different portions of that literature, and for the influence that the literature exerted on the varnas and the caste-system, on the splitting up of the brahmanas themselves among several sub-castes and on the institution of gotras and pravaras.

Early European scholars generally paid scant attention for an in depth study of Yajnas and endeavoured to understand the meaning of Vedas principally by reference to grammar, comparative philology and the comparison of several passages containing the same word or words. Chronology given by them was based mostly on subjective consideration and prompted by the great prejudice felt by the European scholars generally against admitting any great antiquity for the Vedas. It is beyond the scope of this work to enter into any discussion about the dates of various sections of the Vedic Literature.

व्युत्पत्तिः ॥ Etymology

Yajna is a word which represents many symbolic associations of man and devatas, the creation and denotes a rite (mandatory ritual), a praise, a form of worship, an offering or oblation (of substance), an intent, a resolve, an instrument (to achieve purushardhas), an act. It is a word which does not have an exact equivalent english word for it.

• Yajna is derived from the root यज् । Yaj used in the meaning देवपूजासङ्गतिकरणदानेषु (Ashtadhyayi Dhatupatha 1.1157). देवपूजा is to worship a deity and paying one’s respect to it.

• Fifteen synonyms of Yajna according to Nighantu are used for the term ‘Yajna’ in general sense though there are many features which differ among themselves.

  यज्ञः । Yajna, वेनः। Vena, अध्वरः। Adhvara, मेधः। Medha, विदथः। Vidatha, नार्यः। Narya, सवनम्। Savana, होत्रा। Hotra, इष्टिः। Ishti, देवताता । Devatata, मखः। Makha, विष्णुः। Vishnu, इन्दुः। Indu, प्रजापतिः। Prajapati, घर्मः। Dharma इति [यज्ञस्य पञ्चदश यज्ञनामानि] । १७ ।(Nigh. Shas. 3.17)

• Apastamba Paribhasha Sutras and the Commentary by Kapardisvamin about Yajnas is as follows:

  यज्ञं व्याख्यास्यामः। (Apas. Pari. 1.1)

  स तु यज्ञो देवतोद्देशेन द्रव्यत्यागत्मकः याग इति क्रियाविशेषः । स हि निश्श्रेयसाय चोदितः। (Comm. for 1.1 by Kapardisvamin)

  Defining Yajna, the commentary gives the explanation of the Sutra 1.1, as follows:

Yajna, is a special act of offering by which one surrenders dravya (द्रव्य । substance) as offering for devatas, while reciting mantras. It has originated for Nihshreyasa (निश्श्रेयस्) i.e., for the spiritual freedom of all beings.

• Jaimini Purvamimamsa Sutras state the following

यजति चोदनाद्रव्यदेवताक्रियं समुदाये कृतार्थत्वात् -४,२.२७ (Purv. Mima. 4.2.27)

देवतोद्देशः

Yajna Related Definitions

The word Yajna is closely related to other acts of offering havis or oblations into the sacred fire and in a few instances are not specifically related to Vedic rites. Since the term Yajna is used in a general sense interchangeably, for clarity a few words are presented here.

Yajna

As discussed previously, Yajna, broadly is a special act of offering dravya to devatas into the fire along with the recitation of prescribed mantras. Example : Panchamahayajnas are nityakarmas, to be performed daily by grhastas. Mantras recited here are prescribed in Shrauta Sutras and Grhyasutras, for example, Haviryajna procedures are described in Brahmanas and Vedanga Kalpa,

Yagam

They involve elaborate activities on a large scale (building of Agnichayana), extending from more than 12 days to a number of years, involving various offerings made into the fire, requiring not only the four Rtviks (Adhvaryu, Hotr, Udgata and Brahma) but others upto 16 in number for complicated yagas (Somayaga). The mantras used here are prescribed in the Vedanga Kalpas as Shrauta sutras. Example : Somayaga, Sattrayaga, Rajasuya yaga.

Homam

Homam is generally a small scale 'yaga' performed at home or lately conducted as a small community event, unlike the Yaga which requires a large public place where attendance of a large group of persons is expected.

Yajnas in Rig Veda

We find that even in the remotest ages when the mantras of the Rig Veda were composed and compiled, the main features of Yajnas have been evolved. To mention a few instances

• Existence of three fires (Tretagni) appears in Rigveda (2.36.4) where Agni is asked to sit down in three places.
• Rigveda (1.15.4 and 5.11.2) states that men kindle Agni in three places.
• The Garhapatya fire is expressly named in Rigveda (1.15.12)
• The three savanas (i.e. pressings of Soma in the morning, mid-day, and evening) are mentioned in Rigveda (3.28.1 mentions pratah-sava, 3.28.4 mentions madhyandina savana and 3.28.5 mentions tritiya savana).
• That the yajna gives food to Agni three times on all days; is given in Rig veda mantras 3.52.5-6, 4.12.1 and 4.33.11.
• It may affirmed that the sixteen priests required in Soma yajnas were probably known to the composers of Rigveda mantras. The names of the sixteen priests is given in Asvalayana Shrauta sutras (4.1.6) and Apastamba Shrauta Sutras (10.1.9). Rigveda (1.162.5) also mentions a few namely Hotr, Adhvaryu, Agnimindha, Gravagarbha, Samsta (prasahstr or mitravaruna) etc.
• Rigveda (2.43.2) mentions Udgata.
• The word purohita occurs very frequently in Rigveda (1.1.1, 3.2.8 etc).
• The yupa (the post to which the yajnapasu is tied) is mentioned in Rigveda (1.162.6). Rigveda (3.8) is full of praise for yupa.
• The instruments used in yajnas such as darvi (Rig. Veda. 5.6.9) sruk (Rig. Veda. 4.12.1 and 6.11.5) juhu (Rig. Veda 10.21.3) are mentioned in numerous places.
• Yajnas were the first dharmas according to Rigveda (10.90.16).

Thus, evidence of performance of yajnas may be seen from Rigvedic period.

Yajnas in Recent Years

Apart from the Rig Vedic instances of yajnas, we can see that the fundamental conceptions of Yajna (sacrifice) are also seen in Indo-European antiquities though the traces are rather faint. But it is quite clear that the yajnas had been much developed in the Indo-Iranian period. There are numerous words indicative of yajnas both in the vedic language and in the ancient Parsi religious books. For example, words like atharvan, ahuti, uktha, barbis, mantra, yajna, soma, savana, stoma, hotr, do also occur in the ancient Parsi religious scriptures.

Though shrauta yajnas are now very rarely performed (except a few simple ones like the Darshapurnamasa and Chaturmasya) they were in great prevalence several centuries before the Christian Era. Centuries before that even after the advent and spread of Buddhism we learn from the inscriptions and literary traditions that rajas and chakravartis often performed the ancient solemn vedic yajnas and glorified in having done so. Many such inscriptions and literary works speak about their prevalence in much later years, a few examples include the following

• Harivamsha (3.2.39-40), Malavikagnimitra (Act 5), Sunga Inscription from Ayodhya (E.I. vol. 20 at p.79) speak of Rajasuya yajna.
• Stone inscriptions from the Guptas period state that Samudragupta performed Asvamedha yajna.
• The Pikira grant of Simahavarman (E. I. vol. 8 at p.162) describes the Pallavas as the performers of many Asvamedhas. Other inscriptions refers to performance of Agnistoma, Vajapeya and Asvamedha.
• We find that Maharajas while making grants often expressed that the object of the grants was to enable the brahmana donees to offer bali and charu and to perform Agnihotra. (Example : Sarasvni plates of Buddharaja, A.D. 609-10, and Damodarpur plates, A.D. 443-44 and 447-48)

During the centuries of muslim domination no help from royalty could be expected and so the institution of Vedic Yajnas languished. In the last hundreds of years or so, solemn shrauta yajnas have been performed only rarely. But since many of the grhya ceremonies as set forth in the Grhya sutras, which closely imitate the shrauta yajnas, formed the first and foremost manifestation of the sentiments of faith and worship in Bharatavarsha.

श्रौतकर्माणि ॥ Shrauta Karmas

Shrauta karmas include the elaborate activities related to Shrauta yajnas and yagas meant for the well-being of mankind. These karmas are so called because their procedures are directly based on the Srutis or instructions given in Vedas. The brahmanas contain the description of yajnas (which last for many days) and different aakhyayikas as part of the Shrauta karmas (for example Haviyagnakandam of Kanvasatapatha brahmana contains the details of Haviryajnas). However, in Kalpas the rules are methodically compiled in Sutra format without the aakhyayika part. Usually, Srauta karmas involve the Chaaturhotr - the four priests (Hota, Adhvaryu, Udgaata, Brahma).

कल्पः ॥ Kalpa

Kalpas (कल्पः) mainly deal with elaborating the Vedic Yajna procedures and is classified under Vedangas. The very name itself means ‘Kalpyate Samarthyate Yaga Prayogo Atra’ which means “The practice of Vedic ritual traditions are explained here”.

Kalpa Vedanga deals with four types of sutras namely,

• Sulbasutras : Practical manuals with mathematical measurements necessary for construction of yajna vedi (sacrificial altar).
• Shrautasutras : Contain procedures for performing great Yajnas (sacrifices) lasting for many days.
• Dharmasutras : Contain spiritual and worldly laws.
• Grhyasutras : Lay down rules for the ceremonies and yajnas involved in everyday life.

The ‘Sulbasutras’ and ‘Srautasutras’ directly deal with the performance of Vedic rituals. These texts provide guidance for the performance of Vedic sacrifices. The performance of Vedic rituals is being continued even in the modern period especially in South India.

श्रौतसूत्राणि ॥ Shrauta Sutras

Shrauta, as the name suggest, refers to the texts which have been derived from the Shruti or the Vedas. The Shrauta sutras contain a very detailed, meticulously accurate and vivid description of the several sacrifices that were performed in ancient times. These works were manuals compiled for the practical purpose of giving directions to those who engaged in such sacrifices. They are based on ancient Brahmana texts, which they quote at every step, many individual sutras being couched in the very language of the Brahmanas.

The Shrauta rituals cover a whole gamut of rituals from the simplest to the most complicated. Most of them are no more practiced, but their study is useful for historical reasons. According to Prof. Radhakrishna Bhat,

"Most of the ‘Haviryajnas’, ‘Agnihotra’, ‘Darsapurnamasa’ and ‘Caturmasya’ sacrifices, the basic ‘Somayajnas’, ‘Agnistomas’ and its varieties, and some culturally and historically important sacrifices like ‘Vajapeya’, “Asvamedha’, ‘Sarvamedha’ etc are found in ‘Yajurveda’ (Adhvaryuveda). Later in ‘Puranas’ the references to Vedic rituals and practices are found. In classical Sanskrit literature some references to Vedic rituals and practices are mentioned. This shows that the Vedic ritual tradition is continued to modern period too without any interruption".

The procedures for Shrauta karmas are compiled in Shrauta Sutras as given in the Kalpa Vedanga. Some of the Shrauta Sutras associated with particular vedas are as follows

• Rig Veda : Aasvalayana and Shankhyayana Srautasutras.
• Krishna Yajurveda :
  • Taittriya Shaka - Baudhayana, Hiranyakesi, Aapasthamba, Vaikhanasa, Vaadula and Kaathaka Srautasutras.
  • Maitrayani Shaka - Maanava, Varaaha Srautasutras.
• Shukla Yajurveda : Katyayana Srautasutras are the only available texts here.
• Sama Veda : Aarsheyakalpa, Kshudrasutras, Jaimineeya, Laatyayana, and Draahyayana Srautasutras.
• Atharvana Veda : Vaitaana Srautasutras are the only available texts here.

The present article is based on the references of Shrauta sutras of Asvalayana, Apastamba, Katyayana, Baudhayana with occasional references to Samhitas and Brahmanas.

Classsification of Yajnas

Yajnas have been classified in different modes. We present here the different classifications of Yajnas based on their origin, time of performance, derivatives, and importance.

• Yajnas are classified into two based on where their procedures have originated, viz.,

1. Shrauta Yajnas based on their Vedic (Shruti) origin.
2. Smarta Yajnas based on Smritis and Dharmashastras.

• Yajnas are classified into three types based on the time when they are performed, namely

1. Nitya (Daily): is that action which is performed daily. They also include other periodic activities such as Amavasya tarpanam, pitr tarpanam.
2. Naimittika (Occasional): is attended to on particular occasion like child birth, weddings etc.
3. Kamya (Optional) : is that which is performed to attain some special purpose such as begetting children (Putrakamesthi) or establishing victory over other kings (Rajasuya).

• Another classification of Yajna or yaga based on principal and subsidiary actions of Yajna include

1. Pradhana (Principal)
2. Anga (Subsidiary)

A ‘Yaga’ is made up of several rituals which has its own principal part (Pradhana). Those that form subsidiary or supplement to this are called ‘Angas’. Some of the rituals may be common to several ‘Yagas’.

• Vedic yajnas/yaagas are divided into two

1. Prakritiyaaga (Model)
2. Vikritiyaaga (Modified)

Vikritiyaagas derive their procedures from the respective Prakritiyagas.

प्रकृतियागम् ॥ Prakritiyaagas

In the Asvalaayana Srautasutra based on the Rig Veda, there are a number yajnas but five among them are regarded as Prakritiyaagas. In the present days Prakriti yajnas mentioned in the Vedas are rarely conducted.

1. होमम् ॥ Homa : Agnihotra is the Prakriti (model) of all Homas
2. इष्टिः ॥ Isthti : Darsapurnamaasa yaga is the Prakriti (model) of all Isthis
3. पशुयागम् ॥ Pasu : Nirudha Pasubandha is the Prakriti (model) of Pasuyaaga
4. सोमयागम् ॥ Soma : Agnistoma is the Prakriti (model) of all the Somayagas.
5. सत्रयागम् ॥ Sattra : Gavaamayana is the Prakriti (model) of all Satrayagas.

विकृतियागम् ॥ Vikritiyaagas

The subsidiary rituals follow their respective principal sacrifices in the performance of different sacrifices. Vikriti Yaganas like Chandika Homa, Veda Samhita Svahakara Yagas, Rudra Yagas are being performed in temples.

In the context the kindling of fire, the Agnihotram mentioned as nitya karma has been discussed here and only a brief mention of Agnihotram as a part of vedic ritual during different occasions has been made.

Aahutis (Offerings) in Agnihotram

Aahuti is an important aspect of Agnihotram. Different types dravayas are offered as aahuti which changes according to the yaagas, the fires being worshipped and purpose of the yaaga. The dravyas or materials being offered in agnihotram are of the following kinds

1. Vegetable source : Soma juice, tila (sesame),
2. Uncooked Animal source : Payaha (Milk) and milk products like dadhi (curds), ajyam (ghee), navanita (butter). Vaapa (animal fat), honey and wine.
3. Cooked Animals/Pasu Offerings : Body parts of Goat, Cow, Sheep and Horse.
4. Cooked : Purodasa (made of powdered rice), Odana (cooked rice), Laajah (baked rice), yavaagu (rice gruel)

Based on the type of yaagas the important aahuti's are

• For Agnihotram : Milk
• For Isthi : Purodasa
• For Pasu : Pasu sacrifice (goat). Aswamedha yaaga - horse.
• For Soma yaagas : Soma juice

 Yajnakunda Vedi

Temples (and in some homes of aahitagni's) have the brick structures for the conduct of agnihotram. Temples also have designated yaaga-shalas.

Pradhana vedi, Uttara vedi are used to set up altars. Mahavedis are used when there is a requirement of wide spaces. Pasuvedis are used in Pasuyaagas. A large vedi, in the shape of Syena (eagle) is used for Somayaga.

Sulva sutras are the texts that describe the dimensions and geometric measurements, materials for constructing the yaaga-kunda. The yaaga-kunda for the three agnis are

1. Gaarhapatya agni - It is placed to the west of the place and kindled in circular shaped kunda.
2. Aahvaniya agni - It is placed to the east of the place, in a rectangular shaped kunda.
3. Dakshinaagni - It is placed to the south of the place, in a semi-circular (ardhachandra) shaped kunda.

Square and triangle shaped vedi's are also used. One yaagashala may contain many kundas for simultaneous performance of Agnihotram.

 सम्भाराः ॥ Sambharas

Dravyas are poured or placed into the agnihotram using special ladles and vessals made of wood are used. A few are as follows

स्रुक्पात्र ॥ Sruk : It is a long ladle, called variously based on the length and is made of wood. The shape of this implement is specific - it has a bowl or depression on top of it to contain the liquid, a beak shaped curved spout to pour out the liquid and a crowtail shaped tail portion or handle for holding. It represent the female principle or Prakriti.

स्रुवा ॥ Sruva : Sruva is a smaller less elaborate ladle to pour liquids. It is smaller than Sruk having a small bowl or depression (diameter about the size of the thumb).

The most common ladles used in yajnas for pouring ajya or ghee into the agnihotram are sruk and sruva.

प्रोक्षणी ॥ Prokshani : It is a vessel that has a bowl or depression shaped like a lotus bud or leaf with a spout and . It is deep enough to hold water used for prokshana or purification of articles or dravyas. This water is purified by the placing of darbha blades.

स्थाली ॥ Sthaali : Various kinds of clay bowls. These bowls are used to hold milk, ajya aagrayana etc.

स्फ्य ॥ Sphya : It is a wooden sword for cutting the darbha-grass to the required size, for marking lines in yagashala for construction of kunda, for stirring boiled dravyas like purodasa, removing the upper layer of mud and digging the earth.

शम्या ॥ Shamyaa : A wooden peg or small stick or staff having a rounded edge and looks like a mace. It is a measuring device used along with Sphya. 

यजमानि ॥ Yajamana

The कर्ता ॥ Karta should be सपत्नीक यजमानि ॥ sapatinika yajamana should perform this homa daily in the morning with milk, obtained separately from the cow reared for this purpose (agnihotra gaabhi).

• If the yajamāna (performer of the sacrifice) goes on a pilgrimage along with his wife, he can carry the gārhapatya fire with him or can ceremonially put it out and perform punarādhāna (re-establishing the fire) on his return. When he dies, the various wooden implements used by him for Agnihotra should be kept on various parts of his body as prescribed and then his body is cremated with the gārhapatya fire.  
• Wife, son, pupil or a priest can perform Agnihotram on behalf of the yajamani in case of emergencies. Agnihotra cannot be performed by a widower, however on remarriage a widower becomes eligible to perform all yajnas. When the yajamana is separated from his wife and he chooses not to remarry, he can instill his wife's idol for the process of the yaaga. Example : Aswamedha yaaga performed by Sri Ramachandra in Ayodhya while his consort Seetadevi was in Valmiki Maharshi's ashram following the sastra laid down exceptions to some situations.(Ramayana reference needed)   

 ऋत्विक् ॥ Priest

The nitya agnihotram is performed by the karta only (given in Grhyasutras), he is the priest for it. When he is unable to perform the nityakarma wife, son or others may be designated for conducting it.

To perform all Srauta yagas, presence of four priests is important. The चातुर्होत्र || chaaturhotra are

Hota : He is the invoker of all devatas, by reciting mantras he invites them to participate in the yagam. Hotaa is the main and oldest priest among others.

Adhvaryu : He is the executor of the yagam. He along with the yajamani play an active role in preparing the yajnavedi, collecting dravyas, cooking havis like purodasa, actual delivery of the aahutis into the fire.

Udgaata : He recites and sings the saamans. The presence of Udgaata and his assistant priests is absolute requirement in Somayagas.

Brahma : He is the protector and supervisor of the yagam. He is termed as the guardian of the yagam.

In case of Agnihotra yagam (as a part of Agnihotram yagam) it is performed by the yajamani or his son, brother, son-in-law on behalf of the the yajamani. Only in the absence of all these persons आध्वर्यु Adhvaryu is the only person who should perform the Agnihotram. 

 अग्नेः प्राधान्यम् ॥ Importance of Agni in Yajnas

The history of performing kratus, yajnas and yagas is quite ancient and their process is described in the Samhitas. Yajnas, yagas, istis, and homas were performed for individual benefit as well as community welfare. While some yajnas were performed by people of all varnas, some like the Rajasuya or Aswamedha yagam were prescribed only for Kshatriyas. Elaborately conducted yagas such as Soma yagas are not performed these days, while Varuna yagam and Kareeresti for propitiating Varuna devata to obtain good rains is performed at regular intervals as temple events for community benefit.

Agni to be tended by a grihastha (nityakarma) is of two types. Sri. Chandrasekharendra Saraswati Swamiji summarizes the following essentials about Smarta and Srautagnis.

"The aupasana fire (lighted at the time of marriage from that of the groom's father) is divided into two in a ceremony called "agniyadhana". One part is called "grhyagni" or "smartagni": it is meant for rites to be performed at home. The second part is srautagni and meant for srauta rites. These two sacred fires must be preserved throughout."

 स्मार्ताग्निः॥ Smartagni

Smartagni (Grhyagni) is also called औपासनाग्निः ॥ Aupasanagni since the daily rite of औपासना ॥ Aupasana is performed in it. This is the fire contained in one "kunda" and so it is called "ekagni". The section in the Apastamba-sutras dealing with rites performed in it is called "Ekagni-kanda"(according to Yajurveda Brahmanas). Thus, this is the Agni used for performing the नित्यकर्म ॥ nityakarmas where a grihastha makes daily offerings of ghee or milk in Agni while reciting the prescribed mantras (given in Grhyasutra texts).

श्रौताग्निः॥ Srautagni

Srautagni is meant for the Srautakarmas (srauta yajnas such as Haviryajnas and Somayajnas). It involves the use of three fires burning in three mounds hence called Tretagni. From the Aupasanagni, by the procedure of Agnyadhanam, Srautaagni also called as the Garhapatyagni is kindled and maintained by the grihastha at the time of the vivaha samskara. One of the three sacred fires (tretagni), called "garhapatya" belongs to the master of the household. It must be kept burning in the garhapatya mound which is circular in shape. The section in the Apastamba-sutra dealing with rites performed in it is called "Tretagni-kanda". One who worships all these three Agnis is called a "Tretagni" or "Srautin".

One who worships the Srauta and Grhyagnis, is called an "Ahitagni". Aupasana (in Smartagni) and Agnihotra (in Srautagni) are the two Nityakarmas to be performed on a daily basis.

श्रौतयज्ञाः ॥ Srauta Yajnas

Gopatha Brahmana (1.5.23) describes the Haviryajnas and Somayajnas as follows

अग्न्याधेयम् अग्निहोत्रं पौर्णमास्यमावास्ये । नवेष्टिश् चातुर्मास्यानि पशुबन्धो ऽत्र सप्तमः ॥ इत्य् एते हविर्यज्ञाः

अग्निष्टोमो ऽत्यग्निष्टोम उक्थ्यः षोडशिमांस् ततः । वाजपेयो ऽतिरात्रश् चाप्तोर्यामात्र सप्तमः ॥ इत्य् एते सुत्याः

Agnyadheyam and Navesti are given Gopatha Brahmana as one of the Haviryajnas, whereas according to Shabdakalpadruma the following are given summarized in the tables

तत्र श्रौताग्निकृत्य- हविर्यज्ञाः सप्त । यथा । आग्न्याधानं तदेवाग्निहोत्रम् १ दर्शपौर्णमासौ २ पिण्डपितृ-यज्ञः ३ आग्रयणम् ४ चातुर्म्मास्यः ५ निरूढ-पशुबन्धः ६ सौत्रामणिः ७ ।

श्रौताग्निसप्तसंस्थाः । यथा । सोमयागः स एवाग्निष्टोमः १ अत्यग्निष्टोमः २ उक्थ्यः ३ षोडशी ४ वाजपेयः ५ स द्बिविधः संस्था कुरुश्च । अतिरात्रः ६ अप्तूर्य्यामः ७ ।

Srauta Yajnas are 14 in number. They are divided into two main groups : Haviryajnas and Somayajnas. Gautama Dharmasutras also mention these yajnas (8.18).

Srauta Yajnas

Haviryajnas	Somayajnas
अग्निहोत्रम् ॥ Agnihotra	अग्निष्टोम ॥ Agnistoma
दर्शपूर्णमास ॥ Darsapurnamasa	अत्यग्निष्टोम ॥ Atyagnistoma
आग्रयण ॥ Agrayana	उक्थ्य ॥ Ukthya
पिण्डपितृयज्ञ ॥ Pindapitryajna	षोडशी ॥ Sodashi
चातुर्मास्य ॥ Chaturmasya	वाजपेय ॥ Vajapeya
निरूढपशुबन्ध ॥ Nirudha Pashubandha	अतिरात्र ॥ Atiratra
सौत्रामणी ॥ Sautramani	आप्तोर्याम ॥ Aptoryam

The most common of these yajnas is the Agnihotra, where daily havis of milk is given in the three fires, every morning and evening. Apart from Agnihotra, Darsapurnamasa (performed on New and Full Moon days) and Chaturmasya (performed at the beginning of three seasons) are also important.

श्रौतसुत्राणि॥Srauta Sutras

Kalpas are one among the Shad Vedangas. Srautasutras classified as one among the Kalpas deal with the rules for the execution of the great yajnas (sacrifices) which last for many days. All the four Vedas have their Srautasutras.

Vedas	Srautasutras
Rig Veda	Avalayana, Sankhyayana
Krishna Yajurveda : Taittriya	Baudhayana, Bharadvaja, Apastamba, Hiranyakeshi, Vaikhanasa, Vadula, Kathaka
Krishna Yajurveda : Maitrayani	Manava and Varaha
Shukla Yajurveda	Katyanana
Samaveda	Arsheyakalpa, Kshudrasutra, Jaiminiya, Latyayana and Drahyayana
Atharvaveda	Vaitana

Besides these above mentioned Srautasutras, there are many others but their texts are not available at present.

 अग्निहोत्रम् ॥ Agnihotram

Agnihotra, is a term specifically applicable to the first and important vaidika yajnas classified among the Srauta karmas - हविर्यज्ञानि ॥ Haviryajnas (offering of havis is made) or homas. It is performed as a daily worship to Agni and also with an intent to fulfill any specific desire . A brief outline of the various aspects about Agnihotram have been summarized as below. Agnihotra

कर्ता ॥ Karta

The कर्ता ॥ Karta should be सपत्नीक ॥ sapatinika (have a wife) which is the main criteria to perform Aupasana.

• According to Taittriya Brahmana (3.3.3.1) one who does not have a patni or wife cannot perform yajnas.

  अयज्ञो वा एषः । योऽपत्नीकः । (Tait. Brah 3.3.3.1)

• He (or his wife) should perform this homa daily in the morning with milk, obtained separately from the cow reared for this purpose (agnihotra gaabhi).
• If the karta goes on a pilgrimage along with his wife, he can carry the gārhapatya fire with him or can ceremonially put it out and perform punarādhāna (re-establishing the fire) on his return. When he dies, the various wooden implements used by him for Agnihotra should be kept on various parts of his body as prescribed and then his body is cremated with the garhapatya fire.  
• Wife, son, pupil or a priest can perform Agnihotram on behalf of the karta in case of emergencies.  
• Agnihotra cannot be performed by a widower, however on remarriage a widower becomes eligible to perform nitya agnihotra. When separated from his wife and he chooses not to remarry, he can imagine or instill his wife's idol for the process.  

हविस् ॥ Havis/Havishya

Milk is the main dravya or Havis offered as Aahuti in the agnihotra with the chanting of "Svaaha".

पयसा नित्यहोमः १ payasā nityahōmaḥ 1 (Asva. Srau. Sutr 2.3.2)

The performer of Agnihotra is obliged to rear a cow primarily for providing milk as havis to devatas. The milk vessel which must be an earthen pot with a straight brim is called ‘agnihotra-sthālī’ and the ladle is called ‘agnihotrahavaṇī.’ Milk products like dadhi (curds), ajyam (ghee) are also offered.

काम्यकर्म ॥ Kaamyakarma

Although performing agnihotra is a regular activity, it is also performed to attain some special desires called as Kaamyakarma with varying aahutidravyas.

यवागूरोदनो दधि समिग्रामकामान्नाद्यकामेन्द्रियकाम-तेजस्कामानां २ (Asva. Srau. Sutr 2.3.2)

yavāgūrōdanō dadhi samigrāmakāmānnādyakāmēndriyakāma-tējaskāmānāṁ 2 (Asva. Srau. Sutr 2.3.2)

Meaning : Yavaagu (gruel of Yavagu rice) is offered for acquiring leadership over villages, and curd is offered for attaining strength.

समिधा ॥ Samidha

Agnaadheya ceremony starts with the collection of arani (the samidha wood) and ends in purnaahuti (offering at the end of ceremony). Once the fire is kindled by Arani, it is maintained by the addition of smaller pieces of wood called Samidhas into the Agni. These pieces of wood are collected with bark and are 10 to 12 inches long. This process is called "Pratyavaroha".Agni samaaropa and pratyavaroha are to be executed by the karta himself and not by others except by his wife who might perform the Pratyavaroha part.

The trees from which samidhas are obtained include : palaasa, asvattha (peepul), nygrodha (banyan tree), sami, aamra (mango), khadira, durva, darbha (kusa grass), bilva (bael) Apaamarga.

सम्भाराः ॥ Sambharas

Dravyas are poured or placed into the agnihotram using special ladles and vessals made of wood are used. A few are as follows

स्रुक्पात्र ॥ Sruk : It is a long ladle, called variously based on the length and is made of wood. The shape of this implement is specific - it has a bowl or depression on top of it to contain the liquid, a beak shaped curved spout to pour out the liquid and a crowtail shaped tail portion or handle for holding. It represent the female principle or Prakriti.

स्रुवा ॥ Sruva : Sruva is a smaller less elaborate ladle to pour liquids. It is smaller than Sruk having a small bowl or depression (diameter about the size of the thumb).

The most common ladles used in yajnas for pouring ajya or ghee into the agnihotram are sruk and sruva.

प्रोक्षणी ॥ Prokshani : It is a vessel that has a bowl or depression shaped like a lotus bud or leaf with a spout and . It is deep enough to hold water used for prokshana or purification of articles or dravyas. This water is purified by the placing of darbha blades.

स्थाली ॥ Sthaali : Various kinds of clay bowls. These bowls are used to hold milk, ajya aagrayana etc.

स्फ्य ॥ Sphya : It is a wooden sword for cutting the darbha-grass to the required size, for marking lines in yagashala for construction of kunda, for stirring boiled dravyas like purodasa, removing the upper layer of mud and digging the earth.

शम्या ॥ Shamyaa : A wooden peg or small stick or staff having a rounded edge and looks like a mace. It is a measuring device used along with Sphya.

पुनराधान पुनराधेय ॥ Punaraadheya and Purnaraadhana

In the event forbidden materials come into contact with Agni, or the Pavitra samidhas or the homa kunda, there would be agni nasha or destruction of agni called "Agnyopaghaata". In such case Punaraadheya or revival of Agni is to be performed with sterner measures. Taittriya Samhita outlines the पुनराधानविधानम् Punaradhanavidhanam.

Either the karta or his wife should be present near the Agnihotram at the time of sunrise and sunset. If both of them leave the house and cross the boundaries of the village or city without tending to the Agni, then on their return Agni Punaraadhana (Agni Sparsa) has to be done. Thus travel for karta at the time of homa or during the Parvadinas (Amavasya, Poornima tithis) is forbidden and Punaraadhana of Agni is a must.

During the time when Asoucham occurs in the family - Rajodosha (menses time for wife), Sutakam (when there is a death or birth in the family) re-instatement of Agni by Punaraadhana process has to be done. Many prayaschitta vidhis are to be performed if the Agni in the homa kunda is spent, lost due to travel, or destroyed. If for 12 days at a stretch homa is not performed (Homa lopa due to any reason) then prescribed Prayaschittas are to be performed by doing samidha samskaara (purification of homa dravyas) and additional Aahutis. This observance of prayaschitta varies according to different sutras. For example : Hiranyakeshi Sutras prescribe prayaschitta after homa lopa for 12 days, Aapasthamba Sutras advise prayaschitta after homa lopa for 3 days.

Both Agnyaadhaana and Punaraadhana are always performed in the evening times.

हवित्री - यज्ञकुण्डम् वेदि वा ॥ Kunda/Vedi

Kunda or Vedi (altar) called as Havitri is another important aspect of yajnas and yagas including those for nitya agnihotra in homes. They are of different sizes and shapes depending on the type of fire and yaga being performed. For temporary domestic purposes in the present days movable copper kundaas are used, while some prepare altars with sand and a few bricks.

ऋत्विक् ॥ Priest

The nitya agnihotram is performed by the karta only (given in Grhyasutras), he is the priest for it. When he is unable to perform the nityakarma wife, son or others may be designated for conducting it.

To perform all Srauta yagas, presence of four priests is important. The चातुर्होत्र || chaaturhotra are

Hota : He is the invoker of all devatas, by reciting mantras he invites them to participate in the yagam. Hotaa is the main and oldest priest among others.

Adhvaryu : He is the executor of the yagam. He along with the yajamani play an active role in preparing the yajnavedi, collecting dravyas, cooking havis like purodasa, actual delivery of the aahutis into the fire.

Udgaata : He recites and sings the saamans. The presence of Udgaata and his assistant priests is absolute requirement in Somayagas.

Brahma : He is the protector and supervisor of the yagam. He is termed as the guardian of the yagam.

In case of Agnihotra yagam (as a part of Agnihotram yagam) it is performed by the yajamani or his son, brother, son-in-law on behalf of the the yajamani. Only in the absence of all these persons आध्वर्यु Adhvaryu is the only person who should perform the Agnihotram.

समिदाधानम् ॥ Samidhadhanam

It is prescribed by sastras that all the dvijas (the ‘twice-born,’ the men of the first three varṇas) are eligible to perform Agnihotra. A brahmachari is initiated into performing Agnihotram during Upanayana with prescribed procedures and is taught the relevant mantras to conduct the agnihotram.

At the time of investing the yagnopaveeta, he is taught to perform daily aahuti in the fire called Praajapatyaagni check.

Brahmachari's should perform two activities - Sandhyavandanam and Samidhaadhanam in Agni everyday in the morning and evening. In Vishnupurana (3.9.3)

उभे संध्ये रविं भूप तथैवामग्निं समाहितः । उपतिष्ठेत्तदा कुर्य्याद्गुरोरप्यभिवागनम्॥

A bachelor should with devotion pray to surya and agni during both sandhyakaalas and also pay respects to his guru.

आग्निवेश्यगृह्यसूत्रम् ॥ Agnivesyagrhyasutram (1.1.4) outlines the process and mantras as follows

अथ सप्त पालाशीः समिध आर्द्रा अप्रच्छिन्नाग्राः प्रादेशमात्रा घृताक्ता अभ्याधापयति ।

Summary : Seven Palasa samidhas which do not have split ends (with their given dimension) along with ghee are to be offered.

अग्नये समिधमाहार्षं बृहते जातवेदसे । यथा त्वमग्ने समिधा समिध्यस एवं मां मेधया प्रज्ञया प्रजया पशुभिर्ब्रह्मवर्चसेनान्नाद्येन समेधय स्वाहा इत्येकाम् । अग्नये समिधौ इति द्वे । अग्नये समिध इति चतस्रः ।

Here in Asvalaayana Grhya sutras also the mantras to be recited during samidhaadhana are given

मन्त्रेण हैके अग्नये समिधमाहार्षं बृहते जातवेदसे तया त्वमग्ने वर्द्धस्व समिधा ब्रह्मणा वयं स्वाहेति ... (Asva. Grhy. Sutra 8.1.21.1)

Samidhaadhaana vidhi outline is given in Balabodhini Sangraham - 3 where the meanings of 13 mantras are explained. It is discontinued after marriage.

औपासन ॥ Aupaasana

During vivaha samskara the one is initiated to enter the grihasta ashram by setting up the आवसथ्याग्निः ॥ Avasatyaagni to the north of the vedi. (Paaraskara Grhya Sutra Adhyaya 1 Kandika 2 Mantra 1)

आवसथ्याधानं दारकाले १ दायाद्यकाल एकेषाम् २ ॥ āvasathyādhānaṁ dārakālē 1 dāyādyakāla ēkēṣām 2 (Paara.Grhy.Sutra. 1.2.1).

Meaning : The setting up of Aavasatya agni is (performed) at the time of wedding. At the time of inheritance according to some.

He receives additional procedures to perform nityakarma. A few features include

• The son lights his aupasana fire during his marriage from his father's aupasana fire. The son's aupasana fire, like his father's must be maintained throughout his life. Thus, without any break, the sacred fire is kept burning in the family generation after generation.
• All the daily ahutis and cooking involve the aupasana fire and pertain exclusively to the individual and his family. Thus, "Grhyakarmas" including the seven pakayajnas involve the aupasana agni or Grhyagni or smarthagani. They are related exclusively to the family and are not very elaborate.
• The seven pakayajnas, samskara rituals like namakarana, upanayana and sraddha must be conducted in the aupasana fire.
• Starting from marriage, a grihasta (along with his wife) offers aahuti twice daily at twilight time (dawn and dusk) in the Gaarhapatya agni, this is also called as Aupasana.
• Aupasana is to be performed by the grihasthas of the three varnas. Valmiki Ramayana in Ayodhya kanda mentions that Sri Ramachandra, a kshatriya, enquires Bharata about tending the Agni in the house.

  कच्चिद् अग्निषु ते युक्तो विधिज्नो मतिमान् ऋजुः | हुतम् च होष्यमाणम् च काले वेदयते सदा || २-१००-१२ (Valm. Rama. 2.100.12)

  Meaning : "I hope that a brahmin who is versed in the traditions, who is intelligent and just, employed in your sacred fires, always informs you in time, about a sacrificial fire having been or going to be fed with oblations."

• Aahutis must be offered to Surya in the morning and Agni in the evening.
• Every grihastha has to maintain the agni until he is prevented by old age or illness or death. In case where he cannot perform it on behalf of him his son, brother or son-in-law. According to Satapatha Brahmana

  एतद्वै जरामर्यं सत्रं यदग्निहोत्रं जरया वा ह्येवास्मान्मुच्यते मृत्युना वा (Sata. Brah. 7.4.1.1)

  ētadvai jarāmaryaṁ satraṁ yadagnihōtraṁ jarayā vā hyēvāsmānmucyatē mr̥tyunā vā (Sata. Brah. 7.4.1.1)

  Summary: this agnihotram is 'jaraamarya satra' because he can get relief from this only if he dies or becomes old.

• Performance of nitya agnihotra is mandated to the grihasta men of all three varnas. If due to any reason, a grihasta has not conducted agnihotra rituals, he can do so after performing the praayaschitta vidhis as given in the Srauta sastras.
• As a nityakriya agnihotra, Anuditahomi's perform homa before sunrise and some Uditahomi's after sunset.
• Mantras for conducting Agnihotra are covered in Krishna Yajurveda's Taittiriya Samhita in Kanda 1(the 5th Prapathaka contains the mantras for पुनराधेयम् and अग्न्युपस्थानम् )
• Morning aahutis are made to the deities Surya and Prajapati, while the evening aahutis are made to Agni and Prajapati.

• Nitya agnihotra is not to be performed by an uninitiated bachelor or widows.

आहीताग्निः ॥ Aahitagni

Aahitagni is the sapatinika yajamani who has established the fires by performing the Agnyadhana ceremony. He who worships Ekagni (Grhyagni) as well as the Tretagni (one of the Tretagni called Garhapatya) is known as Aahitagni. One who worships all the three Agnis (Tretagni) is called a "Srautin".

• The grihastha who never performed any Haviryajna and never studied Vedas, and whose father or forefathers never performed yaga are not eligible to perform some yagas/yajnas. Example : Somayaga.
• Eligibility for a grihastha to perform other yagas or yajnas will be obtained once he regularly performs Aupaasana at his house on a daily basis and after he learns the relevant vaidika procedures to conduct them . For example: Agnisthoma is the first of the 5 Jyotisthomas or Somayaga. Performance of haviryajna and some isthis is a prerequisite for conducting a Somayaga.

The tradition of ‘Aahitagnis’ and ‘Srauta priests’ continues in South India and they perform Vedic rituals as and when possible. These priests inherited the tradition of Vedic ritual practices from their ancestors and perform Vedic rituals even today.

पञ्चमहायज्ञाः || Panchamahayajnas

पञ्चमहायज्ञाः || Panchamahayajnas are described in many Grhyasutras. According to Asvalayana Grhyasutras

अथातः पञ्चयज्ञाः १

देवयज्ञो भूतयज्ञः पितृयज्ञो ब्रह्मयज्ञो मनुष्ययज्ञ इति २

तद्यदग्नौ जुहोति स देवयज्ञो यद्बलिङ्करोति स भूतयज्ञो यत्पितृभ्यो ददाति स पितृयज्ञो यत्स्वाध्यायमधीयते स ब्रह्मयज्ञो यन्मनुष्येभ्यो ददाति स मनुष्ययज्ञ इति ३

तानेतान्यज्ञानहरहः कुर्वीत ४ १ (Asva. Grhy. Sutr. 3.1.1 to 4)

Meaning : Now the Panchayajnas. The yajna for devatas, yajna for (other living) beings, yajna for forefathers, yajna for Brahma, yajna for human beings.

Here when offerings are made in Agni, this yajna is for the devatas. That which is offered as bali, is the yajna for other beings. That (pindas) which is given for forefathers, is the pitru yajna. That study (of the vedas) is the brahma yajna, and that which given to men, is the manushya yajna. These five yajnas are to be performed everyday.

After the Pratah Homa (according to Hirayakeshi sutras) or after the Madhyaanika Sandhya (according to Asvalaayana sutras) or after the Vaisvedeva, Brahma yajna has to be performed. It includes the study of vedas, itihasas and puranas and slight variations in the timings are seen according to the shakaas followed.

Vaisvedeva is performed as part of pratahhoma (morning) and the evening agnikaryam according to Asvalaayana and Taittriya shakaas. Cooked rice (Anna) is offered in Agni and other deities as part of the Vaisvedeva. Similarly in the Agnihotra homam of Srauta yagas also odanam or cooked rice is offered as havis to different deities.

Yajnas without Agnihotram

Invocation of Agni in a vedi (altar) and offering of aahutis is performed in yajnas. However, not all yajnas involve this process. Vaidika yajnas are also categorized into external and internal rituals, depending upon how they are performed.

External rituals are physical, in which visible dravyas such as milk and ghee are offered to devatas.

Internal rituals are mental or spiritual, in which the mind and the senses are withdrawn and engaged in contemplative or meditative practices, which culminated in self-absorption. In the internal rituals, the sacrificial model is internalized or visualized by mind by a process called Parikalpana. The mind and the body become the field or the sacrificial pit, breath becomes fire, whatever that is offered to the body such as food or pleasure becomes the offering. As man moves above in the series of ashramas from grihasta to vaanaprastha, the elaborateness of the yagas also decrease.

Aranyakas deal with a form of meditative yajnas wherein water is offered in place of milk as a substitute for it.

Upanishads deal with yagas as mental processes and fire symbolises jnana.

अग्निहोत्रस्य वैशिष्टम् ॥ Importance of Agnihotra

Rig vedic mantras extol the greatness of Agni extensively, with Agni suktams describing the various roles of Agni.

अग्निहोत्राहुति परिणामरूपत्वात्कृत्स्नस्य प्रपञ्चस्य

Chandogya Upanishad (5th Adhyaya 24th Khanda) clearly lays down the significance of Agnihotra

तद्यथेषीकातूलमग्नौ प्रोतं प्रदूयेतैव्ँ हास्य सर्वे पाप्मानः प्रदूयन्ते य एतदेवं विद्वानग्निहोत्रं जुहोति ॥३॥

Meaning : Just as the Ishika reed would burn, when thrown into the fire, so also would the evils of one knowing this (knowledge) offers the Agnihotra

यथेह क्षुधिता बाला मातरं पर्युपासते । एव्ँ सर्वाणि भूतान्यग्निहोत्रमुपासत इत्यग्निहोत्रमुपासत इति ॥५॥

Meaning : Just as the hungry children wait for the mother, so also all beings wait for the Agnihotra, indeed!

Here the philosophy of Vaisvanara and the importance of Agnihotra have been proclaimed in Chandogya Upanishad.

Shatapatha Brahmana (SB 3.1.3.18) tells us that Agnihotra should be performed by the performer knowing that he will gain the strength and victories gained by Agni who conquered the earth, Vayu, the air and Surya, the sky, with whom he shares the world; and the same text further tells us that the Agnihotra, doubtless, is the Sun.

Agnihotram in Samskaras

Agnihotra is an important component during naimittika karmas such as those of the Shodasa Samskaaras. Almost all the activities of these samskaraas involve the use of Agnihotra where different homas are performed on each occasion which are given in detail in Grhya sutras of different shakaas. However, a few agnikaryas are mentioned here as follows. These homas are performed with the Aupasana Agni mainly by the grihastha, except a few where a priest conducts them.

Pumsavanam and Seemantonnayanam

Pumsavana homa (Apas.Grhy. Sutr. 6.14.3), Ajyabhaga homa and Jayaati homa are performed.

Jaatakarma

The father takes a sachela snanam (bathing with all clothes on him) as soon as he hears the birth of the child. During Abhimarshanam outlined in Aapastamba grhya sutras (Aapa. Sutr. 6.15. 1 to 13) (Taittriya Samhita also gives these mantras), Agnihotra is lit and Raksha homam is conducted in the fire called Sootakagni. Mustard seeds(sashapa) and rice flakes (phaleekarana) are offered as aahuti by the father.

जातं वात्सप्रेणाभिमृश्योत्तरेण यजुषोपस्थ आधायोत्तराभ्यामाभिमन्त्रणं मूर्धन्यवघ्राणं दक्षिणे कर्णे जापः १ (Aapa. Sutr. 6.15.1)

सर्षपान्फलीकरणमिश्रानञ्जलिनोत्तरैस्त्रिस्त्रिप्रतिस्वाहाकारं हुत्वा संशास्ति प्रविष्टे प्रविष्ट एव तूष्णीमग्नावावपतेति ६ (Aapa. Sutr. 6.15.6)

This homa is performed to protect the child from evil forces and other doshas.

Naamakarana

Shaankhyayana Grihya sutras (1.25.1 to 26) mention the installation of Sutakagni as the child is born and into it aahuti is made during Naamakarana.

Choulam and Choodakarana

Though in the present days, many of these karmas are simplified and been done away with, the Grhya sutras lay emphasis on cutting of hair and piercing of the child's ears. Shaankhyayana Grhya sutras (1.28), Aapastamba Grhya Sutras (1.16), Gobila Grhya Sutras (2.9) detail the procedure while Taittriya Brahmana mantras are chanted from Ekagnikandam (2.1).

Vivaha samskara is one of the most important ones of the Shodasa Samskaras.

Paanigrahanam

Agnihotra is initiated at the time of Paanigrahanam during marriage as given in Apasthamba Grhya Sutras (2.4.9 and 10)

अथैनामुत्तरया दक्षिणे हस्ते गृहीत्वाग्निमभ्यानीयापरेणाग्निमुदगग्रं कटमास्तीर्य तस्मिन्नुपविशत उत्तरो वरः ९ (Aapa. Grhy. 2.4.9)
अग्नेरुपसमाधानाद्याज्यभागान्तेऽथैनामादितो द्वाभ्यामभिमन्त्रयेत १० (Aapa. Grhy. 2.4.10)

Meaning : The agnihotram is established, the vara or groom holds the hand of the bride and brings her near Agni. They sit in north south direction. He offers aajya into the fire.

Saptapadi

Saptapadi is where the bride and groom take seven sacred steps around the witnessing Agni which has been started during the events.(Aapa. Grhy. Sutr. 2.4.15)

Antyeshti

It is the last event where the dead body is offered onto the fire with chanting of mantras. (Rig. Veda. 10.16.1)

स्मार्तकर्माणि ॥ Smaarta Karmas

Smaarta karmas are based on the procedures directly given in Smritis. Smritis include the Dharmasastras, though are based on the Srutis (vedas) are modified versions.

Smritis are 18 in number. Upa-smritis are also 18 in number. All aspects of the worldly existence are covered extensively in Smritis, in sutra format on topics including varna-ashrama dharmas, all aspects of relationship between man and woman, rajadharmas, how to conduct daily activities such as eating, cleaning, bathing etc, pujas, yajnas and yaagas, different aspects related to shraddha karmas.

Asvalaayana, Aapasthamba, Baudhayana texts include both Srauta and Smaarta karmas procedures to conduct yajnas.    

Spiritual sense

All activities in the limitless expansion of the universe are said to have generated from a grand eternal यज्ञ || Yajna.

Atharva Veda (9.15.14) describes Yajna as:

अयम् यज्न विस्ह्वस्य भुवनस्य नभेएहि || ayam yajna vishvasya bhuvanasya nabheehiâ ||

Meaning : Yajna as the fundamental process of manifestation of nature.

In physical terms, Yajna (होम | homam, हवन | havan or अग्निहोत्र | agnihotra) is a process of herbal sacrifices in holy fire aimed at the finest utilization of the subtle properties of sacrificed matter with the help of the thermal energy of fire and the sound energy of the mantras. Modern scientific research has also shown significant therapeutic applications of Yajna and also affirmed its potential in purification of environment. 

Literally speaking, Yajna means - selfless sacrifice for noble purposes. Sacrificing ego, selfishness and material attachments and adopting rational thinking, humane compassion and dedicated creativity for the welfare of all - is indeed the best Yajna which should be performed by all human beings. The philosophy of Yajna teaches a way of living in the society in harmony, a living style to promote and protect higher humane values in the society - which is indeed the basis of the ideal human culture.

Vedic yajnas (other names include yagna, yagn, yajnas) are performed to create positive effects and avoid unwanted effects in the different areas of life of individuals and nations and to have the best possible nature support. Many people use the yagna or yajna words instead of yajna, the meaning of it is the same. We use the vedic word because yajnas are based on the knowledge of the ancient saints of vedic tradition. Vedic yajnas are done by specially trained वैदिक पण्डित || vedic pandits (pundits), who are the experts of vedic ceremonies, performances, and who live their lives' according to the rules of vedic tradition. Yajnas are performed through the recitation of sound or vedic mantras to reach certain result. This is vedic music, vedic vibration. It is possible to use them as prevention but it is also possible to use them for promoting the different areas of life. The benefits of the yajna reigning are the vedic health, wealth, harmony and evolution. Head pandit is the expert of ज्योतिष || jyotish (astrologer), that vedic science which can be used to predict the life events of the individuals and which can be the well-grounded base of suggesting the necessary yajna services for a balanced life.

Discussion

Ritual versus knowledge is a much debated topic. Shankara in his commentary on the Brahma Sutras states that the rightful observance of the agnihotra and other rites are meant for those desirous of attaining Heaven and other enjoyments, and the understanding of the rightful doctrine of the Soul is meant for those desirous of emancipation. Reference needed