YV 6.7g

From what is unsupported in the sacrifice the sacrifice comes to ruin; as the sacrifice comes to ruin the sacrificer comes to ruin along with it; in that he completes (the offering) (for Tvastr) with the wives with butter, (it serves) to support the sacrifice, and as the sacrifice finds support, the sacrificer finds support along with it. The offering of the caul [1] has been performed, the offering of the cow is not yet over, then he performs (the offering) (for Tvastr) with the wives; verily he performs it at the right moment; then indeed comes the conclusion. It is for Tvastr; Tvastr of the seed that is spilt moulds forms, him he sets loose as a male among wives; he for him moulds forms. They kill the Soma in that they press it; in that there is (an oblation) of Soma, that is as when they slay for the dead a barren cow. If he were to offer in the northern half or the middle, he would cause conflict with the gods; he offers on the southern half; this is the quarter of the Pitrs; verily in their own quarter he propitiates the Pitrs. They give to the Udgatrs, (the oblation) of Soma has the Saman for its deity; whatever of the Saman they do amiss, that is the atonement for it. They look at [1] (the victim) for Soma is a purifier; verily they purify themselves. He who cannot see himself would be dead. Having made it full all round, he should look at (it), for in it he sees himself; verily also he purifies himself. He whose mind is gone should look at (it), (saying), 'That mind of mine which hath gone away, or which hath gone elsewhere, by means of King Soma, we keep within us'; verily he keeps his mind in himself [2], his mind is not gone. At the third pressing the sacrifice departs from him who has sacrificed to him who has not sacrificed; he offers ghee with a verse to Agni and Visnu; all the deities are Agni, the sacrifice is Visnu; verily he supports the deities and the sacrifice. He sacrifices muttering, for pairing.