Jaiminīya (Talavakāra) Brāhmaṇa 1.212

Having struck down the Asuras by means of day and night, the gods covered them over with the threefold vajra itself. These worlds are threefold; with these worlds they covered them over. Therefore they say: 'The Asuras will not exist again as long as these worlds exist,' for they are covered over by these worlds. The night is the measure of the Agniṣṭoma and of the year. The year has twenty-four half-months; twenty-four are the ukthamadāni of the night. There are three pressings, three rounds (paryāyas). Thereby they make the night possessed of three pressings; and thus they make it equal to the day. The gods, having conquered day and night, led that Āditya toward the west by means of the pressings; by means of the rounds [they led] him toward the east again; with the Āśvina they propped him up in the east. Therefore they say: 'The Āśvina is not to be recited when the sun has risen,' for [if so] they would make him go astray. For him who knows this thus, that Āditya is led to the west by the pressings, brought back to the east by the rounds, propped up in the east by the Āśvina; both day and night are won and secured for him, and the Āditya moves with his rays for his enjoyment.

Now, this Saṃdhi [sāman] is the Rathantara.

Prajāpati gave his own daughter, the Dawn, to Bṛhaspati.

For her, he made this thousand-verse Āśvina [recitation] the bridal procession (vahatu).

He said to the gods: 'Only this [daughter] is mine, that other is yours.'

Therefore, when a kind-hearted man wins a wife, he assigns the bridal procession [to others].

The gods said: 'Let us divide this amongst ourselves.'

They could not agree upon its division.