Mbh 13.79.1a

"'"Vasishtha said, 'The kine that had been created in a former age practised the austerest penances for a hundred thousand years with the desire of attaining to a position of great pre-eminence. Verily, O scorcher of foes, they said unto themselves,--"We shall, in this world, become the best of all kinds of Dakshina in sacrifices, and we shall not be liable to be stained with any fault! By bathing in water mixed with our dung people shall become sanctified. The deities and men shall use our dung for the purpose of purifying all creatures mobile and immobile. They also that will give us away shall attain to those regions of happiness which will be ours."[376]--The puissant Brahman, appearing unto them at the conclusion of their austerities, gave them the boons they sought, saying,--"it shall be as ye wish! Do ye (thus) rescue all the worlds!"--Crowned with fruition in respect of their wishes, they all rose up,--those mothers of both the Past and the Future. Every morning, people should bow with reverence unto kine. As the consequence of this, they are certain to win prosperity. At the conclusion of their penances O monarch, kine became the refuge of the world. It is for this that kine are said to be highly blessed, sacred, and the foremost of all things. It is for this that kine are said to stay at the very head of all creatures. By giving away a Kapila cow with a calf resembling herself, yielding a copious measure of milk, free from every vicious habit, and covered with a piece of cloth, the giver attains to great honours in the region of Brahma. By giving away a cow of red complexion, with a calf that resembles herself, yielding milk, free from every vice, and covered with a piece of cloth, one attains to great honours in the region of Surya. By giving away a cow of variegated hue, with a calf similar to herself, yielding milk, free from every vice, and covered with a piece of cloth, one attains to great honours in the region of Soma.