YV 1.7e

Therefore the Rudras are murderous, for they have no support. Therefore they say, 'The midmost day of the three-day night is not fixed; for it was moved.' The Ajya (Çastra) of the midmost day is in the Tristubh metre. He recites the Samyana hymns, then recites the Sodaçin, that the day may be made firm and be not loose. Therefore in the three-night rite, the first day should be an Agnistoma, then an Ukthya, then an Atiratra, for the separation of these worlds. On each day in succession he gives three hundred continuously [4], for the continuance of these worlds. He should not break the decades lest he should thus destroy the Viraj. Now for the thousandth Indra and Visnu strove. Indra reflects, 'By this Visnu will appropriate all the thousand.' They made arrangement as to it, Indra got two-thirds, Visnu the remaining third; verily the fact is recorded in the verse, 'Ye twain have conquered.' It is the Achavaka [5] who recites this verse. Now (some say), 'The thousandth is to be given to the Hotr'; what is left over, is left over for the Hotr; the Hotr is the receiver of what has not been taken. Then others say, 'It is to be given to the Unnetr.' This is left over of the thousand, and the Unnetr is the one of the priests who is left over. Then some say, 'It is to be given to all those who have a place in the Sadas.' Then some say, 'It should be driven away and allowed to wander at will.' Then some say, 'It is to be given to the Brahman and the Agnidh [6], two shares to the Brahman and the third to the Agnidh. For the Brahman is connected with Indra, the Agnidh with Visnu; (verily the division is) just as they two agreed upon. Then some say, 'The one which is beautiful and of varied colour is the one to be given.' Then others say, 'The one which has two colours and on either side is spotted is the one to be given', for the gaining of a thousand. That indeed is the march of the thousand (sahásrasyáyana).