Jaiminīya (Talavakāra) Brāhmaṇa 2.264

Just as one would silently strike with whips, in the very same way, having fetched all these artistic works, he anoints them in brahman.
'Therefore they are to be sung variously,' [they say].
Indeed, from where these [yokes] are sung variously in this world, from that are Brahmins defeated here.
Now, when they did not sing them variously, the Brahmins were eaters of food.
Driving from afar with a single foot-yoke, on a single cart, Satyayajña Pauluṣi used to travel unassailed [among] cattle.
Now, from where these are sung variously here, from that these artistic works are obtained among Brahmins.
He sings the Gāyatrī before; [he sings] the Gāyatrī after.
The Gāyatrī is brahman.
By means of brahman he thus encompasses these artistic works on both sides.
Encompassed on both sides by brahman, these artistic works attend upon him who knows thus.
'They are not to be sung variously,' say the Pañcālas.
'These yokes are already discordant by themselves.
Singing variously along each pressing, he ascends them.
Now, when ill fame arises following them, saying: "They have sung discordantly!"—
Concerning two who fight, who quarrel, they say: "The two have sung discordantly"; and also regarding two who stand tearing a realm apart—'

they say [the same].

The morning pressing belongs to the Gāyatrī; the midday pressing belongs to the Triṣṭubh; the third pressing belongs to the Jagatī.

To that very [rite] the Anuṣṭubh is appended.

When, the morning pressing being in the Gāyatrī, he sings the Gāyatrī—the Gāyatrī is brahman—it is brahman

that he causes to share in the property of the Brahmin.

If [the Brahmin] wishes to take it, he wishes to offer it to him.

Moreover, it belongs to him alone,

for he causes him to share in his own [property].

Now, when he sings the Triṣṭubh—the Triṣṭubh is dominion—it is the Kṣatriya that he causes to share in the Brahmin's

own [property].