YV 6.3l

When it was pierced (by him) [3] they cut off (a piece) of the size of a barleycorn; therefore one should cut off (a piece) the size of a barleycorn. If one were to cut off more, he would confuse that part of the sacrifice. If he were to make a layer and then to sprinkle, lie would make it swell on both sides. He cuts it off and sprinkles it; there are two operations; the sacrificer has two feet, for support. If he were to transfer it (to the Brahman) crosswise, he would pierce the unwounded part of the sacrifice; lie transfers it in front; verily he transfers it in the proper way. They transferred it for Pusan [4]. Pusan having eaten it lost his teeth; therefore Pusan has pounded food for his share, for he has no teeth. The gods said of him, 'He has lost (his teeth), he is not fit for the offering.' They transferred it to Brhaspati. Brhaspati was afraid, 'Thus indeed will this one fall on misfortune.' He saw this Mantra; 'With the eye of the sun I gaze on thee', he said, for the eye of the sun harms no one [5]. He was afraid, 'It will harm me as I take it.' 'On the impulse of the god Savitr, with the arms of the Açvins, with the hands of Pusan I take thee', he says; verily, impelled by Savitr, he took it with the holy power (Brahman) and with the gods. He was afraid, 'It will harm me as I eat.' 'Thee with the mouth of Agni I eat', he said, for nothing harms the mouth of Agni. He was afraid [6], 'It will harm me when I have eaten.' 'With the belly of the Brahman', he said, for nothing harms the belly of the Brahman. 'With the holy power (Brahman) of Brhaspati', (he said), for he is fullest of the holy power (Brahman). The breaths indeed depart from him who eats this offering; by purifying it with water he grasps the breaths; the breaths are ambrosia, the waters ambrosia; verily he summons the breaths according to their He takes a portion for the Agnidh; verily he delights the seasons whose mouth is Agni.