Jaiminīya (Talavakāra) Brāhmaṇa 14.60

For this day belongs to the Bṛhant.
“Flow for great refreshment, rich in cattle, O Drop, rich in gold, / rich in horses, O Soma, rich in heroes” —
thus there are [verses] containing cattle [and] containing livestock, for the securing of livestock.
“Flow, O watcher over all! Fill the great two worlds, / as the sun, the dawn with its rays” —
thus there are [verses] containing the sun.
For this day is dedicated to Sūrya, twenty-one-fold, a firm foundation, belonging to the Virāj.
“Around us, with a stream bringing protection, O Soma, from all sides / run like sap to the summit” — thus there are [verses] containing “around” (pari-), which is the form of the end.
For this day is an end.
“Run swiftly, O high-minded one, around with your dear domain, / where the gods,” so they said;
“adorning what is unadorned”;
“This is he who from heaven around” —
thus it contains “around, around”; that is the form of the end.
The end of the meters, truly, is the Anuṣṭubh;
this day belongs to the Anuṣṭubh.

It consists of six verses; six indeed are the seasons — for the attainment of the seasons.

Regarding this they say: “Since a six-verse hymn is the characteristic mark of the sixth day, why then is it performed on the fourth day?”

He should say: “Six indeed are the seasons; the year [is six seasons]. The year is Prajāpati; [it is] the sacrifice.

Having obtained the year, Prajāpati, the sacrifice by this means, they begin anew at the opening of the soma pressing.

For the sacrifice is, as it were, completed when this preceding three-day period is completed.”

The latter [hymn] consists of six verses.

Thereby they undertake the sacrifice in proper succession.

“The beams urge on the sun” —