Mbh 3.207.1a

“Markandeya continued, ‘The pious fowler, O Yudhishthira, then said to that Brahmana, ‘Undoubtedly my deeds are very cruel, but, O Brahmana, Destiny is all-powerful and it is difficult to evade the consequence of our past actions. And this is the karmic evil arising out of sin committed in a former life. But, O Brahmana, I am always assiduous in eradicating the evil. The Deity takes away life, the executioner acts only as a secondary agent. And we, O good Brahmana, are only such agents in regard to our karma. Those animals that are slain by me and whose meat I sell, also acquire karma, because (with their meat), gods and guests and servants are regaled with dainty food and the manes are propitiated. It is said authoritatively that herbs and vegetables, deer, birds and wild animals constitute the food of all creatures. And, O Brahmana, king Sivi, the son of Usinara, of great forbearance attained to heaven, which is hard to reach, giving away his own flesh. And in days of yore, O Brahmana, two thousand animals used to be killed every day in the kitchen of king Rantideva; and in the same manner two thousand cows were killed every day; and, O best of regenerate beings, king Rantideva acquired unrivalled reputation by distributing food with meat every day. For the performance of the fourmonthly rites animals ought to be sacrificed daily. ‘The sacred fire is fond of animal food,’ this saying has come down to us. And at sacrifices animals are invariably killed by regenerate Brahmanas, and these animals being purged of sin, by incantation of hymns, go to heaven. If, O Brahmana, the sacred fire had not been so fond of animal food in ancient times, it could never have become the food of any one. And in this matter of animal food, this rule has been laid down by Munis:--Whoever partakes of animal food after having first offered it duly and respectfully to the gods and the manes, is not polluted by the act.