YV 1.2b

The beard is the characteristic of man, the lack of horns of the horse, having incisors on one side only that of cattle, having sheep-like hooves that of sheep, the goat-nature that of goats; so many are the domesticated animals; verily by their characteristics he wins them [5]. He who desires cattle should offer one of a triplet to Soma and Pusan; the she-goat has two teats, two are born separately, the third for strength and growth. Verily he has recourse to Soma and Pusan with their own share; verily they produce cattle for him; Soma is the depositor of seed, Pusan the producer of cattle; Soma deposits seeds for him, Pusan produces cattle. The sacrificial post is of Udumbara; the Udumbara is strength, cattle are strength; verily by strength he wins for him strength and cattle. Prajapati created offspring; they being created went away from him; they went to Varuna; he pursued them and asked them back; he would not give them back to him; he said, 'Choose a boon, and then give them back to me.' He chose a boon from them, it was the black (beast) with one white foot. He who is seized by Varuna should offer this black (beast) with one white foot to Varuna. Verily he has recourse to Varuna [1] with his own share; verily he sets him free from Varuna's noose. It is a black (beast) with one white hoof, for it has Varuna for its deity (and serves) for prosperity. Svarbhanu, the Asura, pierced the sun with darkness; the gods desired an atonement for him; the first darkness of his they struck off became a black sheep; the second a bright-coloured one; the third a white one; what they cut from the upper part of the bone became a barren ewe [2]. The gods said, 'Here has come into being a divine beast; to whom shall we offer him?' Now then the earth was small, plants were not born, they offered the barren ewe to the Adityas as desire.' Then the earth became broad, the plants grew.