Tretagni (त्रेताग्निः)

All Srauta yajnas or yagas are associated with त्रेताग्नयः the three Agni's, and hence also called Srautaagni. However, not all three fires are lighted and maintained at all times. त्रेताग्नयः the three fires are kindled in performance of yagas. Somayagas require the kindling of all three fires whereas others do not require so.

Tretagni and Ekagni

The section in the Apastamba-sutras dealing with the offerings made in the three fires is called "Tretagni-kanda". One who worships the three Agnis is called a "srauti" and if he worships the srauta and grhya fires, he is called an "ahitagni". Ekagni is the sacred fire in which the the chaitanyam of the creating-energy is meditated and Vhree (Rice grain) is offered to the Agni with recitation of prescribed mantras and is called as Aupasana. If aupasana is a grhyakarma, Agnihotra is a srauta karma and it too must be performed twice a day.

A few important features of the three agnis are summarized below

गार्हपत्याग्निः ॥ Garhapatyaagni

Information about of गार्हपत्याग्निः ॥ Garhapatya agni

• It is kindled after marriage, and is be maintained and worshipped for the rest of the life by the grihastha along with his wife.
• It is ceremonially established with the elaborate vedic procedure involving recitation of specific mantras during the process called Agnyadhana. The Aupasana Agni lit at the time of the grooms wedding is passed on from the father to the son. It is divided into two during the Agnyadhana process. One part becomes the Grhyagni and the other becomes the Srautagni called Garhapatya.
• It is the only Agni that is maintained continuously and daily aahutis are to be made to this Agni by the grihastha.
• It is used by grihastas for general domestic usage, to cook food and offering of aahutidravyas used in other yajnas by reciting mantras.
• It is placed to the west of the yajnavedi and placed in circular shaped kunda in Srauta yajnas.
• It is rekindled by a special process involving the Prayaschitta mantras called "Punaradhana" if it gets extinguished for any reason.
• It is used in nityakarmas.
• It is the source of other two Agnis.
• Only a sapatnika yajamani (grihastha) of the three varnas is allowed to tend this Agni.

आहवनीयाग्निः ॥ Aahvaniyaagni

Some salient aspects about आहवनीयाग्निः ॥ Ahvaniya agni are as follows

• It is invoked only in special aabhicharika yaagas unlike Garhapatya agni.
• Ahvaniya agni is established from the Garhapatya agni along with the recitation of specific mantras.
• It is not maintained everyday and is considered as Laukikagni at the end of the specific yaaga for which it is invoked.
• It is placed to the east of the yajnavedi, in a rectangular shaped kunda.
• It is used to offer aahutis to the devatas only during Srauta yajnas.

दक्षिणाग्निः ॥ Dakshinaagni

Salient aspects about दक्षिणाग्निः ॥ Dakshinaagni is as follows

• It is invoked only in special yaagas similar to Ahvaniya agni.
• Dakshinaagni is established from the Garhapatya agni along with the recitation of specific mantras during yajna karmas.
• It is not maintained everyday and is considered as Laukikagni at the end of the specific yaagam for which it is invoked.
• It is placed to the south of the yajnavedi, in a half circle shaped kunda.
• It is used to offer aahutis to the pitrudevatas or forefathers only.