Shatapatha Brahmana 4.5.9.3

4.5.9.3

taṃ gṛhītvā na sādayati | prāṇā vai grahā netprāṇānmohayānīti mohayeddha prāṇānyasādayettaṃ dhārayanta evopāsate 'tha grahān gṛhṇātyatha yadā grahān gṛhṇātyatha yatraivaitasya kālastadenaṃ hiṃkṛtya sādayatyathaitatprajñātameva pañcamamaharbhavati tadaindravāyavāgrān gṛhṇāti

Having drawn that (Âgrayana) cup, he does not deposit it--the grahas being the vital airs--lest he should disorder the vital airs; for he would indeed disorder the vital airs, were he to deposit it. They sit near holding that (cup); and (the Adhvaryu) draws (the other) cups; and while he draws the cups, then whenever the time of that cup (in the order of performance comes), he utters 'Him' and deposits it. Then follows that normal fifth day; on that he draws the cups beginning with the Aindravâyava.