Indra and Vrtrasura (इन्द्रः वृत्रासुरः च)

Vrttrasura (Samskrit : वृत्रासुरः) the son of Tvastr Prajapati, is an important asuric force about whom mantras are mentioned extensively in the Rig Veda. Indra, slays Vrttra with his Vajraayudha and is greatly praised for his valor and deeds in many suktas of Rig Veda. Indra as a lokapalaka and devaloka rakshaka plays a very important role in protection of Dharma and its followers such as other devatas, rishis and pious people. It is to be noted here that Vrttra came into being with the sole aim of killing Indra.

परिचय ||Introduction

The most important work of Indra is to stop those energies and powers which are against the flow of life or creation. There is no other personality who is given more importance than Vrttra in the Vedas and there is no other symbolic story as is Vrttraasura vadha or killing of Vrttra.

Vedas describe a continuous battle between  Asuras (demons) and suras (devas).  Every moments result of the battle decides whether there will be flow of life or a regression. There are varieties in the asuric powers or asuric energy. Amongst them Vritra is most important.

व्युत्पत्तिः || Etymology

Vritra has been defined by Yaska as follows

तत्को वृत्रः। मेघ इति नैरुक्ताः । त्वाष्ट्रोऽसुर इत्यैतिहासिकाः । अपां च ज्योतिषश्च मिश्रीभावकर्मणो वर्षकर्म जायते । तत्रोपमार्थेन युद्धवर्णा भवन्ति । (Nirukta 2.16)

tatkō vr̥traḥ। mēgha iti nairuktāḥ । tvāṣṭrō'sura ityaitihāsikāḥ । apāṁ ca jyōtiṣaśca miśrībhāvakarmaṇō varṣakarma jāyatē । tatrōpamārthēna yuddhavarṇā bhavanti । (Nirukta 2.16)

Meaning : Nirukta defines Vrttra as the cloud, which is a water body. From the historical perspective Vrttra is Tvaashtra (the son of Tvashtra). A combination of water and lightning (electricity) gives rise to the process of rain and this process is used as a simili to describe a war.

इन्द्रवृत्रयोः युद्धविचारः || Indra and Vrttra War Viewpoint

In Taitreya Samhita and Satapata Brahamana the fight between Indra and Vrttra, the cause and consequences of the battle, has been described.

Sruti explains in many places

na tvam yuyuthse katham usche nahan narhate tete mitro maghavan kascanasti mayatsyani yuyudhyahuhu nadya shatrum na purayu yutsuhu Shatpata Brahman 12.1.6.10

The Rig veda mantras also describe the symbolism of the wars of Indra as follows

यदचरस्तन्वा वावृधानो बलानीन्द्र प्रब्रुवाणो जनेषु । मायेत्सा ते यानि युद्धान्याहुर्नाद्य शत्रुं ननु पुरा विवित्से ।। (Rig Veda 10.54.2)

yadacarastanvā vāvr̥dhānō balānīndra prabruvāṇō janēṣu । māyētsā tē yāni yuddhānyāhurnādya śatruṁ nanu purā vivitsē ।। (Rig Veda 10.54.2)

Meaning 2nd line: Hey Indra you don’t have a battle with anyone, and even so how can any enemy match you? All those who say you fought battles are nothing but maya (illusion) for you do not have any enemies in the past?

Discussion (Dr K L Narayanacharya's Veda Samskrita Parichaya): To consider that Vritra was in charge of one of the tribes before Aryans came to India and the fight between Vrtra and Indra — who is portrayed as the God of the Aryans viewing the entire episode from a modern historical perspective and concluding that Indra is a historical person - one should very well see these the import of these Rig Veda mantras.

Indra, the most amazing power and energy assuming different kinds of forms for the sake of well-being of the universe, is an aspect mentioned in many places of the Vedas. Therefore the battle between Indra and Vritra is symbolically very significant and has to be seen from this perspective and not from a historic viewpoint.

Vrttrasura Vadha as in Taitreya Samhita

In Taitreya Samhita the story is mentioned in this way: Trashtra prajapathi had a son named Vishwarupa.  

वि॒श्वरू॑पो॒ वै त्वा॒ष्ट्रः पु॒रोहि॑तो दे॒वाना॑मासीथ्स्व॒स्रीयोऽसु॑राणा॒न्तस्य॒ त्रीणि॑ शी॒ऱ्षाण्या॑सन्थ्सोम॒पान सुरा॒पान॑म॒न्नाद॑न॒॒ स प्र॒त्यख्षं॑ दे॒वेभ्यो॑ भा॒गम॑वदत्प॒रोख्ष॒मसु॑रेभ्यः॒ सर्व॑स्मै॒ वै प्र॒त्यख्ष॑म्भा॒गं व॑दन्ति॒ यस्मा॑ ए॒व प॒रोख्षं॒ वद॑न्ति॒ तस्य॑ भा॒ग उ॑दि॒तस्तस्मा॒दिन्द्रो॑ऽबिभेदी॒दृङ्वै रा॒ष्ट्रं वि प॒र्याव॑र्तय॒तीति॒ तस्य॒ वज्र॑मा॒दाय॑ शी॒ऱ्षाण्य॑च्छिन॒द्यथ्सो॑म॒पानम् [1] (Arsheya System 1.2.22.1 and Saraswat system 1.2.5.1.1)  

Once the purohit of the devathas: Brihaspati, being angry, he left his priestly work and so the devathas invited Vishwarupa as their priest and Vishwarupa had some inclination towards the demons. Therefore without the devathas noticing, he would offer some of the oblations to the asuras, which was arranged by, devas.

When Indra got to know about this, he was furious and killed Vishwarupa. When Trashtra got to know about this, he was very upset and performed a yajna to get a son who could kill Indra. Trashtra perfomed yajna without inviting Indra. He did not invite him to drink Soma pana. Indra told Trashtra that he should invite him and Trashtra said since you have killed my son, I’ll not and he performed his yajna without Indra and Indra by force without the permission of Trashtra drank Soma pana during the conclusion of yajna.  

त्वष्टा॑ ह॒तपु॑त्रो॒ वीन्द्र॒॒ सोम॒माह॑र॒त्तस्मि॒न्निन्द्र॑ उपह॒वमैच्छत॒ तं नोपाह्वयत पु॒त्रम्मे॑ऽवधी॒रिति॒ स य॑ज्ञवेश॒सं कृ॒त्वा प्रा॒सहा॒ सोम॑मपिब॒त्तस्य॒ यद॒त्यशि॑ष्यत॒ तत्त्वष्टा॑हव॒नीय॒मुप॒ प्राव॑र्तय॒त्स्वाहेन्द्र॑शत्रुर्वर्ध॒स्वेति॒ स याव॑दू॒र्ध्वः प॑रा॒विध्य॑ति॒ ताव॑ति स्व॒यमे॒व व्य॑रमत॒ यदि॑ वा॒ ताव॑त्प्रव॒णम् [36] Arsheya System 4.5.36.1 and Saraswat system 1.2.4.12.1)  

Being angry with Indra, Trashtra used left over Soma and invoked Havan-agni and took that left over soma and went to ahavana agni and then he blazed the fire and performed the homa and chanted sva indra chatru vardhasya. While chanting this mantra there was some mistake in pronunciation and because of that mispronunciation, the entire meaning got changed. Instead of let there be a son who could kill indra, it became, let there be a son who will be killed by Indra. Instantly, Vritra was born and started expanding over the entire universe.  

 == Vajraayudha ==

आसी॒द्यदि॑ वा॒ ताव॒दध्य॒ग्नेरासी॒त्स स॒म्भव॑न्न॒ग्नीषोमा॑व॒भि सम॑भव॒त्स इ॑षुमा॒त्रमि॑षुमात्र॒व्विँष्व॑ङ्ङवर्धत॒ स इ॒माल्लोँ॒कान॑वृणो॒द्यदि॒माल्लोँ॒कानवृ॑णो॒त्तद्वृ॒त्रस्य॑ वृत्र॒त्वन्तस्मा॒दिन्द्रो॑ऽबिभे॒दपि॒ त्वष्टा॒ तस्मै॒ त्वष्टा॒ वज्र॑मसिञ्च॒त्तपो॒ वै स वज्र॑ आसी॒त्तमुद्य॑न्तुं॒ नाश॑क्नो॒दथ॒ वै तऱ्हि॒ विष्णुः॑ [37] Arsheya system 4.5.36.2 and Saraswat System 1.2.4.12.2)  

Vrithra means one who grows or goes in circles and Indra was unable to control the Vritra. Meanwhile Vritra’s father, Trashtra became repentant and became fearful and he gave a special thunderbolt and made it powerful by invoking certain mantras and offered it to Indra. Vedas describe Vajrayudha as "tapovysa vajra asit" meaning "tapasaya itself is the Vajrayudha (thunderbolt). Indra could not lift Vajrayudha and prayed to Srimahavisnu.  

अ॒न्या दे॒वता॑सी॒त्सोऽब्रवी॒द्विष्ण॒वेही॒दमा ह॑रिष्यावो॒ येना॒यमि॒दमिति॒ स विष्णु॑स्त्रे॒धात्मानं॒ वि न्य॑धत्त पृथि॒व्यां तृती॑यम॒न्तरि॑ख्षे॒ तृती॑यं दि॒वि तृती॑यमभिपर्याव॒र्ताद्ध्यबि॑भे॒द्यत्पृ॑थि॒व्यां तृती॑य॒मासी॒त्तेनेन्द्रो॒ वज्र॒मुद॑यच्छ॒द्विष्ण्व॑नुस्थितः॒ सोऽब्रवी॒न्मा मे॒ प्र हा॒रस्ति॒ वा इ॒दम् [38] (Arsheya system 4.5.36.3 and Saraswat System 1.2.4.12.3) 

Mahavisnu pleased with Indra's and prayers of other devatas, divided himself into 3 parts "विष्णु॑स्त्रे॒धात्मानं॒" Vishnus tredhatmanam. It indicates His Trivikrama tattva. One third part of Vishnu's energy was placed in the earth, another one third in devaloka and the last third was placed in the Antariksha or Space.  

मयि॑ वी॒र्यं॑ तत्ते॒ प्र दास्या॒मीति॒ तद॑स्मै॒ प्राय॑च्छ॒त्तत्प्रत्य॑गृह्णा॒दधा॒ मेति॒ तद्विष्ण॒वेति॒ प्राय॑च्छ॒त्तद्विष्णुः॒ प्रत्य॑गृह्णाद॒स्मास्विन्द्र॑ इन्द्रि॒यं द॑धा॒त्विति॒ यद॒न्तरि॑ख्षे॒ तृती॑य॒मासी॒त्तेनेन्द्रो॒ वज्र॒मुद॑यच्छ॒द्विष्ण्व॑नुस्थितः॒ सोऽब्रवी॒न्मा मे॒ प्र हा॒रस्ति॒ वा इ॒दम् [39] (Arsheya system 4.5.36.4 and Saraswat System 1.2.4.12.4) 

मयि॑ वी॒र्यं॑ तत्ते॒ प्र दास्या॒मीति॒ तद॑स्मै॒ प्राय॑च्छ॒त्तत्प्रत्य॑गृह्णा॒द्द्विर्मा॑धा॒ इति॒ तद्विष्ण॒वेति॒ प्राय॑च्छ॒त्तद्विष्णुः॒ प्रत्य॑गृह्णाद॒स्मास्विन्द्र॑ इन्द्रि॒यं द॑धा॒त्विति॒ यद्दि॒वि तृती॑य॒मासी॒त्तेनेन्द्रो॒ वज्र॒मुद॑यच्छ॒द्विष्ण्व॑नुस्थितः॒ सोऽब्रवी॒न्मा मे॒ प्र हा॒र्येना॒हम् [40] (Arsheya system 4.5.36.5 and Saraswat System 1.2.4.12.5) 

Indra then merged himself with Visnu's energy of prithvi and with that strength was able to lift the vajrayudha. Seeing this Vrttra removed himself from the earth and continued the battle in space and in heavenly planets. Indra with the blessing of Mahavishnu then defeated Vritra who entered into a truce with indra. 

इ॒दमस्मि॒ तत्ते॒ प्र दास्या॒मीति॒ त्वी (३) इत्य॑ब्रवीत्स॒न्धान्तु सं द॑धावहै॒ त्वामे॒व प्र वि॑शा॒नीति॒ यन्माम्प्र॑वि॒शेः किम्मा॑ भुञ्ज्या॒ इत्य॑ब्रवी॒त्त्वामे॒वेन्धी॑य॒ तव॒ भोगा॑य॒ त्वाम्प्र वि॑शेय॒मित्य॑ब्रवी॒त्तव्वृँ॒त्रः प्रावि॑शदु॒दरं॒ वै वृ॒त्रः ख्षुत्खलु॒ वै म॑नु॒ष्य॑स्य॒ भ्रातृ॑व्यो॒ यः [41] (Arsheya system 4.5.36.6 and Saraswat System 1.2.4.12.6)  

Vritrasura said allow me to enter into your body. Indra asked him what will you do with me? Will you eat me? Vritra replied that he will become the fire in the stomach, as hunger (jataragni) in humanbeings.  

In this way Vritra entered into the body of Indra and the living entities and continues to stay in the form of hunger. He is called as भ्रातृ॑व्यो॒ brathravya and those who understand this, they will conquer hunger.  

ए॒वं वेद॒ हन्ति॒ ख्षुध॒म्भ्रातृ॑व्य॒न्तद॑स्मै॒ प्राय॑च्छ॒त्तत्प्रत्य॑गृह्णा॒त्त्रिर्मा॑धा॒ इति॒ तद्विष्ण॒वेति॒ प्राय॑च्छ॒त्तद्विष्णु॒ः प्रत्य॑गृह्णाद॒स्मास्विन्द्र॑ इन्द्रि॒यं द॑धा॒त्विति॒ यत्त्रिः प्राय॑च्छ॒त्त्रिः प्र॒त्यगृ॑ह्णा॒त्तत्त्रि॒धातो॑स्त्रिधातु॒त्वं यद्विष्णु॑र॒न्वति॑ष्ठत॒ विष्ण॒वेति॒ प्राय॑च्छ॒त्तस्मा॑दैन्द्रावैष्ण॒वद्ग ह॒विर्भ॑वति॒ यद्वा इ॒दं किंच॒ तद॑स्मै॒ तत्प्राय॑च्छ॒दृच॒ः सामा॑नि॒ यजूद्गं॑षि स॒हस्रं॒ वा अ॑स्मै॒ तत्प्राय॑च्छ॒त्तस्मा॑त्स॒हस्र॑दक्षिणम् [42] (Arsheya system 4.5.36.7 and Saraswat System 1.2.4.12.7)  

In this way because of accepting the valor of Vritra three times through Indra, Visnu is called Tridaatu. Also the special ingredient called purodasa is offered to Indra and Vsnu, therefore also it is called trudatu uktahaa vith tridathu. In this episode, the main cause of Indra’s valor is Visnu himself.  

Keno Upanishad explains that the parakrama or valor of all the devathas, the bhagvatha himself is responsible for it. We can recollect this. Mostly all the victories of Indra, Indra’s valor, Indra’s glorification all these suktas are basically glorifying the lord who is residing in the devathas. The Vedas are glorifying paramatma or bhagavan who is the inner dwelling soul of Indra. That’s how it should be taken, and for this there is ample evidence  

indrasya yajna yajja satha In the Vsnu Sukta, part of Rk Samhita Sri Sayana Acarya he gives Taitreya Samhita as the example: the Rk Bhaga is 1.22.19 

There are many points here to be observed Vritra was not killed here but he was given a place in every living entity as hunger. There is an important and a very interesting understanding here. There is a concept of eternal reality here. Therefore the disturbance to the living entity is an eternal experience in this world, symbolically, hunger is the sign of dissatisfaction. Gita explains Kama esa krodha esa rajo guna samudbava mahasano mahapapma viddhy enam iha vairinam 3.37

The hunger which is in the form of kama and krodha

Lust and anger is insatiable hunger. In the 16th chapter of Bhagavad Gita it is explained: Kamam asritha duspuram and duspurena analenaca repeatedly the kama is compared to the inexhaustible fire. Those who are very much hungry it is said that there is a ghost sitting in them. It’s a village way of saying. Here Vritra is such ghost who is in the belly  . Such ghost had affected Indra. This is explained in the Ramayana shudda chaiva sahasrakham brahma hatya samavishat Bala Kanda 14.15.

The above episode is explained in Tairteya , that since then all the living entities are affected by Vritra and entered into their belly. Therefore the devathas are closely connected to human beings and there is even a chance that they could be affected by Vritra. At the same time, whatever benefits the devathas got, the humans also got benefitted indirectly.

In this way Vritra is called vranothervan vartathervan, vardadervan on who walks by creating circles, who is always existing, who always grows. In that sense, he is the eternal enemy: kama, krodha and personification of sins. That is how Vedas define. But those who still doubt, can read the verse from Srimad Bhagavatham 6.9.18 yenāvṛtā ime lokās tapasā tvāṣṭra-mūrtinā sa vai vṛtra iti proktaḥ pāpaḥ parama-dāruṇaḥone who is in dark form or form of ignorance, darkness, from that Trastra covers the 3 planets, personification of sin, the most destructive power is called Vritraha.

Vritra’s deeper description

the Vedas explain or describe Vritra in this way

athrushnavantham viyatham buddimanam sushupanam indra sapta prati pravatha sayana mahim vajrena virihena aparvanan Rk Samhita 4.19.10 (It is 4.19.3)

Vrita is called as having a very bulky body and he is but not very powerful, personification of dissatisfaction, unconscious, but doesn’t not recognize that. He sleeps in a way that that sapta sindus can’t flow, he is shaped in a snake form.  Such Vritra is killed by Indra with his thunderbolt, on the day of full moon light. Vedas describe the death of Vritra in many places.

The mood of this is the birth of Vritra and killing of Vritra is an eternal principle of this world therefore it is explained that

vratra ahim parishaya maranaha he is lying facing against flowing water. That means life is a continuous flow and no one can stop it. The community life is one kind and the individual life is another kind of flow: bhu, bhuva, suvaha. The 7 vyaharthris they represent the elevation of one’s consciousness. Therefore sapta sindhus they represent the consciousness of the 7 planets of human existence. So therefore this indicates the flow of consciousness in the human existence. We will describe in a different volume on this subject matter. Water is the ingredient that keeps things green, without water there is drought. Similarly in the personality of human beings, if the flow of life or the sapta sindus stop, then there is a drought of spiritual existence, then every aspect of human beings, the emotions, intellectual capacity, friendship, values, relationships, it gives rise to drought like situation. In this way the flow of ruthu or the season is to not to stop is the nature of this world that is the desire of the lord. ruthum ruthaya pavathe and specially those who are on the path of ruju marga, it always flows in a way pleasing and favorable to them and to sleep and  stop that flow of water is the main work of Vritrasura. As we described previously panis are the robbers of spiritual knowledge of God. But Vritra is the one who stops the flow of life. He is the one who puts obstacle for human beings to achieve higher realms of life and that gives him happiness. In the water there is a principle of svara-loka and agni deva was the one who killed Dasyus and he released this planet and therefore there is connection between water and paramapada.

This connection is spoken in vedas also

agnir jatho arochathaha grihan dasyun jyotisha tamaha avindath ga apaha svaha Rk Samhita 5.14.4. (Rik is matching)

In many places this connection is given.

apsu surya vahad dhanam  the sun god who is residing in water, he has lots of wealth of the devathas. 8.64.9 (Rik not matching)

When Vasishta offered his prayer and glorified the water based on the revelation of this verse. RS 7.49.1 (Rik is matching)

Samudra jeshtaha salilasya Madhya punaha yantha minisha manaya indroya vajro vrishabo ra rath tha apo de virahimamavanthu Rk Samhita 7.49.1

the water flow from river which are continuously flowing for reaching the ultimate destination: ocean, then the flow between sky of ocean and purify the entire existence. One who is transcendentally situated just like Vajri Indra he fulfills everyone’s desire from freeing from  Vritra imprisonment. So similarly let the situation of the water flow, let it protect me or let it flow continuously.

The river which is flowing from the ocean, there is one very interesting thing, in earthly planet we see river flowing towards ocean. But here rivers are being born from the ocean (samudra is always superior and it is also salilasya madhyath) this one is symbolic and there is no doubt about it because if you just try to get the meaning, this sukta doesn’t give any explanation or meaning, but in the personality of human being, to recognize or revitalize the consciousness which is dormant, and when it is re-awakened, then most of the time, it is flowing outwards.

In this way life’s transaction goes on. So this one is the rain coming from space and from that perspective, the internal thing is explained. In the future suktas it is explained that this transcendental river is born in devaloka and it flows uninterruptedly and then it re-appears svayam jaha and this river is flowing only for the ocean and Varuna is called the master and he is always watching the satya and unrutha: the truth and falsity. Such daivi descriptions are there.

Samudra has been defined by Yaska Niruktha 12.10 has one of the sixteen meanings of antariksha is samudravanthi aspath apaha samudra samabhidravanthi enam apaha sa vodanthe asmin bhutani samudako bhavathi samono uthyathi va that means water is created and everything is flowing towards water. Every living entity is happy then water enters there and water is making everything wet and this one the ocean that is described here is different from the oceans of the earthly planet. Therefore one of the most important work of Vritra is to stop water flow and that means to stop flow of life. That’s symbolic meaning and therefore to control him and restrict him, that’s the main duty of the devathas or Indra specifically. In this work, the Marut devathas helped Indra. This is explained in Aitreya Brahamana 3.20 similarly in many places the Vedas glorify this. The help of Vsnu is described in previous verses and many devathas have invested their energies in Indra and that’s what is explained

Soma and Agni in Vrita’s face

Let’s describe more the killing of Vritra. Taitreya Samhita 2.5.2 explains, Trashtra prajapathi wanted a son who would kill Indra but because of some change in pronunciation, Vritra was born to be killed by Indra. This we discussed previously. One who was growing like a big sized bow, his own father supported his killing. Indra took the shelter of Prajapathi. He took blessings from him and after making the most powerful thunderbolt, he came to fight Vritra and when Vritra was facing Indra, there were 2 devaths: Agni and Soma. They prayed: Oh Indra please do not kill him because he is our residence. For this Indra said, you are mine and you should give up your different facets and come to me and I kill everyone. Everyone was offering havirbhava and yajna havribhaa was offered. Instead of thanking him they asked for some share in yajnas and Indra, he offered ekadasaka pala havirbhava on the day of paurnamasa by visualizing in the yajna. Then they couldn’t come out of the jaws, they prayed oh Indra, we have been caught in the jaws of Vritrasura, we cannot save ourselves and then Indra because of his sankalpa: resolve, he created a fever which was very cold in nature. Vritra being sick due to the fever and very exhausted and yawned very loudly and Agni and Soma suddenly they came out,  suddenly Vritra’s prana and apana they gave up on him. Here Vritra’s life air is considered as pranovau dakshopanaha krituhu he is called daksha and the apana is called krituhu. daksha is expert in work. Krutu: deha samarthya. Therefore those who have lost the power of action and lack of physical strength, he is considered as dead like Vritra. Whenever performing yajna and if there is disturbance in any part of the body and if yawning happens it is called mayi daksho krito this mantra should be chanted. But one who understand this secret he doesn’t experience sheeta jvara-- cold fever. In this way Agni and Soma went inside the body of Vritra and came out. When Vritra was not willing to be killed, Indra came to kill him.

In the clutches of Vritra, Dyava and Prithvi

At that time Dyava and Prithvi they stopped him and explained, don’t kill him because he has covered the entire planetary system from bhumi to dyu loka. If you kill him, it’s like killing us as he took our shelter. And Indra did not agree. That time dyava and prithvi asked for benediction. Dyava requested that he should always stay with the stars and bhumi devi said I should stay with reptiles, birds, animals, lata, gulma, rivers, mountains and so many colorful items should be always available. Indra agreed to their proposals and killed Vritra on a full moon light. Vritra vadhi happens on full moon. Therefore full moon light is called vartaagni. That means the darkness which is covered that enemy has to be killed. That’s the import.

The teja of the devathas from Vritra’s body brought by the Cows

Then after Indra addressed Agni and Soma, he said that just like in the past you should bring havya in the yajna for us. They said, since we are stuck in the jaws of Vritra, we have lost our teja--brightness. Till we get it back, we can’t get your oblation or havishya. That time the devathas sent the gomatha to bring the teja. Because it is said gauravau sarvasya mitramiti cow is a friend of everybody, the cow agreed upon this and asked for a benediction: If she could bring the teja from the body of Vritra then what ever comes from her: the milk, ghee in that let there be the power of devathas and Indra agreed upon this and in this way the teja of Agnis in the ghee and soma’s teja in the milk and in the other ingredients, the power of devathas is hidden. This is explained by Sruthi very interestingly.

Some more Explanation: In the above description there are certain very interesting points that we should focus on. Even the devathas are stuck in the jaws of Vritrasura . There is a warning here. It shows if Vritra is allowed to grow then the consequences are negative. This is the import of the story.

Second important principle of Vritra’s behavior is that he destroys the splendor of those light which lights of the universe.  He destroys our faith, confidence, devotion, physical strength and affection/attraction to right path, our focus, our medha shakti etc., whatever is powerful and splendorous, to  destroy them that is the goal of Vritra. Even after Vrtra’s death, the impact on Agni and Soma was very powerful. One can understand how strong Vritra is?  Therefore only for the cow (that means the power of the devathas that was lost) it was possible to bring back the power of Agni and Soma.  So we can understand that all the power of devathas is hidden in gavya: cows.   There is no limit how much one can speak about the greatness of Cow.  In reality and  also symbolically we have discussed the greatness of cow.  We need to understand this more deeply. 

Indra created cold fever, to release Agni and Soma from the clutches of Vrtra.  There is a significant point here.  It appears that diseases or roga come to minimize the power of demons. By the power of the devatas, and also by the power of Visnu, Vrithra was killed. 

There is no contradiction to say some places Vritra was killed and in other places he had truce between indra and Vrtra decided to stay in the belly of Indra in the form of hunger.   In one perspective, the battle between indra and Vritra is eternal. Therefore in that sense Vritra did not die completely. Therefore it is said he entered into Indra. Out of 100 forts, Indra destroyed 99 and 1 survived. This is what Vedas say, Rk Samhita 7.19.5. In many places Vritra has been described that out of 100 places, 99 were killed and one survived. This is described in one place: Rk Samhita 1.83.14 that means the aspect of Vritra is still there. Sometime the Vritra is described as Vritre as a she-demon. That means the sinful energy can come in any gender. From other perspective, the Rishis who have mercy of God, are able to control Vritra who is there in different form within the Rishis, according to time, place and circumstances. Therefore Vritra’s death has to happen with certain rules and limitations. That means for one person, he may be dead but for other person, he is surviving still. This is how this story has to be understood from a symbolical and deeper perspective.

The Power of Thunderbolt (Vajrayudha): When the question comes with which weapon, Indra killed Vritra? It is explained that Indra killed Vritra by vajrayudha. It is explained in Vedas, itihaas, purana. Let’s try to understand some significant explanation of this weapon. In this explanation it is interwoven with the story of Dadichi the son of Atharva from the Angirasa gothra indro dadicho astabhihi vritranya pratishnuthaha jagan avathirnavaha 1.84.13 In many of the suktas and in many parts of Taitreya Samhita,  what to speak of that-- in all the branches of veda, the story of how dadichi bones were helpful for indra to make vajrayudha/thunderbolt is mentioned and he killed Vritra navateernava that means 810 times he killed and in some other places it is said 99 Vritras were killed by Indra.

Story of Dadichi Rishi: Previously Dadichi the son of Atharva putra when he was living simply when he glanced the asuras they were defeated. jivatho darshanena after sometime by the power of time factor, when he went back to heavens and earth was filled by many demons and indra got defeated and was not able to fight demons. That time they came looking for this Rishi.They realized that this Rishi has gone to the heavens, then when they inquired with those people who stayed with Rishi, they asked if there is anything that is left over, that is connected to Dadichi Rishi?,  Any of his bodily limb? Etc?  Indra was thinking that as Dadichi was a great Rishi and every part of his body is affected by tapsasya had the power to restrain the demons. That’s how Indra understood. That time those who have served Dadichi they have told Indra by narrating another story and assisted Indra. Previously to get madhu vidya, Dadichi maharshi who received from Indra and he had also taken shelter of Aswini Devathas. But Dadichi had one restriction: if he shares that vidya to others, then his head will explode. Then Aswini devatas had suggested a good idea to replace the head of Dadichi Rishi with a horse head and then after receiving the madhu vidya then the head will fall off and they could replace his original head back. Therefore they said the head of the horse was unknown to us and when Indra ordered to search, they found that it had fallen in Kurukshetra in a lake called sharyanavatha and they found it. And then Indra made Vajrayudha from the skull of the horse that is how Sayana Acarya explains in many places.

The description by Skanda Swami: Skanda Swami in his purport, he narrates this story little differently. Previously kala kanja the demons defeated devatas in the war and they came to Brhama and Brhama sent them to Dadichi maharshi and told them to give ability to defeat demons and devathas came to Dadichi maharshi ashram and Dadichi maharshi sitting in yoga and by the power of yoga he renounced his body and through his bones, Indra created thunderbolt. The story of Dadichi maharshi getting a horse head is described in Rk Samhita 1.117.22 and the head or skull was found in Saryanavathi. This is described in Rk Samhita 1.84.13. Saunaka maharishi in Brihad devatha  explains in 3.19.4.  

Another very significant point here:  Ashwini kumuaras, who received the braham svarupa, hayasirasu. That hayasirasu was removed and fell in saryanavathi. But along with that, horse head was offering benediction to all living entities and time to time it would come from the lake and go down again. This is going to  happen till yuga. tad bhath samuthaya bhutebyo vividhan varan pradhaya yuga pariyantham tasmai vasunimajjathi(3.9.24 Bhr, dev)