YV 1.6g

He scratches himself with the horn of the black antelope and smiles, holding it for the protection of his offspring. He should not let go the horn of the black antelope before the bringing of the gifts (to the priests). If he were to let go the horn of the black antelope before the bringing of the gifts, the womb of his offspring will be liable to miscarriage. When the gifts have been brought, he casts away the horn of the black antelope in the pit. The pit is the womb of the sacrificer; the horn of the black antelope is the womb; verily he places womb in womb, that the sacrificer may have a womb. Speech went away from the gods, not being willing to serve for the sacrifice. She entered the trees. It is the voice of the trees, the voice that is heard in the drum, the lute, and the flute. In that he offers the staff of the initiated, he wins speech. The (staff) is of Udumbara wood; the, Udumbara is strength; verily he wins strength. It is level with his mouth; verily from the mouth (downwards) he wins strength for him. Therefore from the mouth they enjoy strength [1]. After the buying of the Soma he hands the staff to the Maitravaruna (priest). For the Maitravaruna first assigns to the priests their utterance, and the priests plant it in the sacrificer. 'Hail! with my mind the sacrifice', he says; for man approaches the sacrifice with his mind. 'Hail! from heaven and earth', he says; for the sacrifice is in heaven and earth. 'Hail! from the broad atmosphere', he says; for the sacrifice is in the atmosphere. 'Hail! from the wind the sacrifice I grasp', he says [2]. The sacrifice is he who blows here; verily he clearly wins him. He clenches his fist; he restrains his speech, for the support of the sacrifice. 'This Brahman has consecrated himself', he says thrice in a whisper; verily he proclaims him to the gods. Thrice aloud (he says it); verily he proclaims him to both gods and men. He should not utter speech until the Naksatras appear.