Jaiminīya (Talavakāra) Brāhmaṇa 31.183

Viśvāmitra desired: "May I win this race!"
He saw these two sāmans.
With them he drove them back as he encircled them.
They carried him through.
They won.
Then indeed he won that race.
Those who advance from the sixth day to the Chandomas go as if against the stream.
Therefore, that the Rohitakūlīya is here is for victorious conquest.
He wins, who knows thus.
And it is a granter of desires.
He desired this desire;
this desire of his was fulfilled.
Whatever desire one has when praising with this sāman, that desire of his is fulfilled.
And because he won at the bank (kūle) with the two bay horses (rohitābhyām), therefore they are called "Rohitakūlīyas."
"O Soma, being purified, in a stream"—
thus the Bṛhatī is of twofold form.
This [verse] indeed sustained both sāmans; therefore, those who have the Bṛhat-sāman use this, and those who have the Rathantara-sāman use this.

Upon them, the Raurava [is sung].

The gods tore off these unexhausted forms for battle against the Asuras.

Agni tore off the Raurava.

With it he burned against the Asuras.

Being scorched, they cried out (aravanta).

Because they cried out when being scorched, that is the Raurava-ness of the Raurava.