vi. 4. 9.

The head of the sacrifice was cut; the gods said to the Açvins, Ye are physicians; do ye replace the head of the sacrifice', they replied. Let us choose a boon; let there be drawn a cup for us also herein.' For them they drew this cup for the Açvins; then indeed did they replace the head of the sacrifice; in that (the cup) for the Açvins is drawn, (it is) to restore the sacrifice. The gods said of these two, 'Impure are they, wandering among men [1] and physicians.' Therefore a Brahman should not practise medicine, for the physician is impure, unfit for the sacrifice. Having purified them by the Bahispavamana (Stotra) they drew for them this cup for the Açvins; therefore (the cup) for the Açvins is drawn when the Bahispavamana has been sung. Therefore by one who knows thus the Bahispavamana should be performed; verily he purifies himself. Their skill as physicians they deposited in three places, in Agni a third, in the waters a third, in the Brahman a third. Therefore one should put beside him a pot of water [2] and sit on the right hand of a Brahman when practising medicine; all medicine he performs thereby, his remedy becomes effective. The theologians say, 'For what reason are cups for two deities drawn in one vessel, but offered in two?' In that (the cups) are drawn in one vessel, therefore there is one breath within; they are offered in two vessels, therefore the breaths outside are in pairs. Those that are for two deities are the breaths, the Ida is cattle; if he should summon the Ida before those that are for two deities [3], he would obstruct his breaths by cattle, he would be likely to perish. Having eaten those for two deities, he summons the Ida; verily having placed the breaths in himself he summons the Ida. (The cup) for Indra and Vayu is speech, that for Mitra and Varuna is the eye, that for the Açvins is the ear; he eats in front that for Indra and Vayu, therefore in front he speaks with speech; in front that for Mitra and Varuna, therefore in front he sees with the eye; moving all round, that for the Açvins; therefore on all sides he hears with the ear. Those for two deities are the breaths [4], he sets down full vessels; therefore the breaths are full within; wherever in the performance of the sacrifice nothing is done, in that place the Raksases attack the sacrifice; in that he sets down full vessels the part of the sacrifice being performed is deposited to prevent the entry of the Raksases. He sets down in the north track of the southern oblation-cart; verily he places speech in speech. They lie (there) until the third pressing, for the continuity of the sacrifice.