YV 2.7d

If a man be a long time ill, he should sacrifice with (the rite) of nine nights; for his breaths are loosened, and thus is he ill long; verily he supports his breaths in him, and even if his life be gone, yet Prajapati desired, 'May I be propagated.' He saw this Daçahotr, and offered it. By this he created (the rite) of ten nights, and by this (rite) often nights he was propagated. If one is about to consecrate oneself for (the rite) of ten nights one should offer the Daçahotr; verily he creates by the Daçahotr (the rite) of ten nights, and by (the rite) of ten nights he is propagated. The sacrifice of ten nights is connected with the Viraj. He, who knowing thus sacrifices with (the rite) of ten nights, attains the Viraj. The sacrifice of ten nights is connected with Prajapati [1]. He, who knowing thus sacrifices with (the rite) of ten nights, is propagated. Indra was on a level with the gods, he was not separated from them. He ran up to Prajapati; he gave him this (rite) of ten nights. He grasped it, and sacrificed with it. Then indeed he became separated from the other gods. He, who knowing thus sacrifices with (the rite) of ten nights, attains separation from the evil enemy. The sacrifice of ten nights has three eminences [2]; the Pañcadaça (Stoma) is one eminence; the Ekavinça one eminence, the Trayastrinça one eminence. He, who knowing thus sacrifices with (the rite) of ten nights, becomes thrice eminent among his peers. The sacrificer is the Pañcadaça; the sacrificer the Ekavimça, the sacrificer the Trayastrinça, and the others are the citadels. If a man have witchcraft practised against him, he should sacrifice with (the rite) of ten nights; verily he surrounds himself with the divine citadels; no harm whatever can befall him, the practiser of witchcraft overcomes him not. The gods and the Asuras were in conflict. The gods [3] saw in (the rite) of ten nights the divine citadels.