Mbh 12.268.2a

"'Bhishma said, "Both courses of duty are highly blessed. Both are extremely difficult of accomplishment. Both are productive of high fruits. Both are practised by those that are admittedly good. I shall presently discourse to thee on the authoritativeness of both those courses of duty, for dispelling thy doubts about their true import. Listen to me with concentrated attention. In this connection is instanced the old narrative of the discourse between Kapila and the cow. Listen to it, O Yudhishthira![1225] It has been heard by us that in days of old when the deity Tvashtri came to the place of king Nahusha, the latter, for discharging the duties of hospitality, was on the point of killing a cow agreeably to the true, ancient, and eternal injunction of the Vedas. Beholding that cow tied for slaughter, Kapila of liberal soul, ever observant of the duties of Sattwa, always engaged in restraining his senses, possessed of true knowledge, and abstemious in diet, having acquired an excellent understanding that was characterised by faith, perfectly fearless, beneficial, firm, and ever directed towards truth, uttered this word once, viz.,--'Alas ye Vedas!'--At that time a Rishi, of the name of Syumarasmi, entering (by Yoga power) the form of that cow, addressed the Yati Kapila, saying, 'Hist O Kapila! If the Vedas be deserving (in consequence of those declarations in them that sanction the slaughter of living creatures), whence have those other duties (fraught with entire harmlessness to all creatures) come to be regarded as authoritative?[1226] Men devoted to penances and endued with intelligence, and who have the Srutis and knowledge for their eyes, regard the injunctions of the Vedas, which have been declared through and compiled by the Rishis, to be the words of God himself.