Jaiminīya (Talavakāra) Brāhmaṇa 4.15

Vajra Āṅgirasa, desiring cattle, practiced austerities.
He saw this sāman; he praised with it.
He reached this iḷā.
Cattle indeed are iḷā.
Then indeed he obtained cattle.
This is a cattle-granting sāman.
He obtains cattle, he becomes rich in cattle, who knows thus.
Because Vajra Āṅgirasa saw it, therefore it is called the Vajra.
Now the Yaudhājaya has three finales, for the arrangement of the pressings.
Now the Auśana is the final sāman, so that by the final sāman we may attain the final heavenly world.
Now the Rathantara.
The Agniṣṭoma is brahman; the Rathantara is brahman.
Standing firm in brahman they go forth.
Now the Vāmadevya.
Cattle indeed are the Vāmadevya.
Possessing cattle indeed they become, having praised with this.
Now the Naudhasa.
Sharing the same world indeed are the Kāleya and the Rathantara.

"Forward the somas dripping intoxication"—thus there are Gāyatrī verses containing [the word] "forward" (pra) for the Ārbhava Pavamāna on a Rathantara day. For this day is one on which they wish to advance. "Forward" is the form of the Gāyatrī. With the form of the Gāyatrī they advance. They contain [the word] "intoxication" (mada). Intoxication is indeed sap. The third pressing is as it were drained. Since these [verses] contain [the word] "intoxication", they place sap in it; they swell it with sap.