Mahabharata 13.75.8

13.75.8

sa tāmekāṃ niśāṃ gobhiḥ samasakhyaḥ samavrataḥ |
aikātmyagamanātsadyaḥ kalmaṣādvipramucyate || 8 ||

The giver, thus residing with the kine in the fold without doing anything to restrain their freedom, and lying down on the bare earth (without driving away the gnats and other insects that would annoy him as they annoy the kine), becomes immediately cleansed of all his sins in consequence of his reducing himself to a state of perfect similitude with the kine. When the sun rises in the morning, thou shouldst give away the cow, accompanied by her calf and a bull. As the reward of such an act, heaven will certainly become attainable to thee. The blessings also that are indicated by the Mantras will also be thine. The Mantras contain these references to kine: Kine are endued with the elements of strength and energetic exertion. Kine have in them the elements of wisdom. They are the source of that immortality which sacrifice achieves. They are the refuge of all energy. They are the steps by which earthly prosperity is won. They constitute the eternal course of the universe. They lead to the extension of one's race. Let the kine (I give away) destroy my sins. They have that in them which partakes in the nature of both Surya, and Soma. Let them be aids to my attainment of heaven. Let them betake themselves to me as a mother takes to her offspring. Let all other blessings also be mine that have not been named in the Mantras I have uttered!