YV 3.7d

The Tryaha is reversed, for the return (from heaven), and for support. Having prospered in either world they cease (the rite). The (nights) are fourteen. As for ten of them, the Viraj is ten-syllabled, the Viraj is food; verily by the Viraj they win food. As for four, the quarters are four; verily they find support in the quarters. There are Atiratras on either side, for security. Indra was on a level with the gods, he was not distinguished from them. He ran up to Prajapati; he gave him this (rite) of fifteen nights. He grasped it, and sacrificed with it. Then indeed he became distinguished from the other gods. Those who knowing thus perform (the rite) of fifteen nights attain distinction from the evil enemy. The three days are Jyotis, Go, and Ayus. The Jyotis is this (earth), the Go the atmosphere [1], the Ayus yonder (sky); verily they find support in these worlds. There can be no Sattra where there is no Chandoma; in that there axe Chandomas, there is the Sattra. The gods they win by the Prsthas, the cattle by the Chandomas. The Prsthas are force and strength, the strength, and in cattle, they Chandomas cattle; verily in force and find support. (The rite) is of fifteen nights; the bolt is fifteenfold; verily they hurl the bolt at their enemies. There are Atiratras on either side, for securing power. Indra was as it were loose and unfixed. He was afraid of the Asuras. He ran up to Prajapati; he gave him this (rite) of fifteen nights as a bolt. With it he overcame and conquered the Asuras and attained prosperity. By the Agnistut he burned away the evil, by (the rite) of fifteen nights he placed force, might, power, and strength in himself. Those, who knowing thus perform (the rite) of fifteen nights overcome and conquer their enemies and attain prosperity. By the Agnistut they burn away the evil [1], by (the rite) of fifteen nights they place force, might, power, and strength in themselves. These (nights) are full of cattle.