In the Chaitanya Charitamrita, the traditional biography of Gaudiya Vaishnava founder Chaitanya Mahaprabhu, a Muslim Kazi asks Chaianya Mahaprabhu about the Gomedha Yagna, a Vedic fire-ritual where cows were sacrificed. Here is his response:
As a learned scholar, the Kazi challenged Caitanya Mahāprabhu, “In Your Vedic scriptures there is an injunction for killing a cow. On the strength of this injunction, great sages performed sacrifices involving cow-killing.”
Refuting the Kazi’s statement, the Lord immediately replied, “The Vedas clearly enjoin that cows should not be killed. Therefore every Hindu, whoever he may be, avoids indulging in cow-killing. In the Vedas and Purāṇas there are injunctions declaring that if one can revive a living being, one can kill it for experimental purposes. Therefore the great sages sometimes killed old cows, and by chanting Vedic hymns they brought them back to life for perfection. The killing and rejuvenation of such old and invalid cows was not truly killing but an act of great benefit. Formerly there were powerful brāhmaṇas who could make such experiments using Vedic hymns, but now, because of the Kali-yuga, brāhmaṇas are not so powerful. Therefore the killing of cows and bulls for rejuvenation is forbidden.”
My question is, why does Chaitanya Mahaprabhu say that cows sacrificed in the Gomedha Yagna were brought back to life? Is he right that there are references "in the Vedas and Puranas?"
This seems rather strange to me, because the Vedas have plenty of descriptions of the afterlife of the sacrificed animal. The Sri Vaishnava Acaharya Ramanujacharya cites various such Vedic verses in the Sri Bhashya, his commentary on the Brahma Sutras:
For Scripture declares that the killing of sacrificial animals makes them to go up to the heavenly world, and therefore is not of the nature of harm. This is declared in the text, 'The animal killed at the sacrifice having assumed a divine body goes to the heavenly world'; 'with a golden body it ascends to the heavenly world.' An action which is the means of supreme exaltation is not of the nature of harm, even if it involves some little pain; it rather is of beneficial nature.--With this the mantra also agrees: 'Thou dost not die, thou goest to the gods on easy paths; where virtuous men go, not evil-doers, there the divine Savitri may lead thee.'
It seems odd that those scriptural passages wouldn't mention the soul of the sacrificed animal coming back into its own body.
This chapter of the Drona Parva of the Mahabharata says the same thing about the Yagnas of the great king Rantideva (whom I discuss in my answer here):
Of rigid vows and always engaged in due performance of sacrifices, countless animals, desirous of going to heaven, used to come to him of their own accord. So large was the number of animals sacrificed in the Agnihotra of that king that the secretions flowing from his kitchen from the heaps of skins deposited there caused a veritable river which from this circumstance, came to be called the Charmanwati.
So clearly the animals didn't come back to life if their skins were heaped up.
In any case, does anyone know what scriptures Chaitanya Mahaprabhu had in mind when he made his statement?