Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 24.4.8

24.4.8

tad ya evam vidvāṃsa etam tryaham ubhayato viṣuvantam upayanti /

xxiv. 3. Svarbhānu, an Asura, pierced with darkness the sun; the Atris were fain to smite away its darkness; they performed, before the Viṣuvant, this set of three days, with the Saptadaça Stoma. They smote away the darkness in front of it; that settled behind ; they performed the same three-day (rite) after the Viṣuvant; they smote away the darkness behind it. Those who perform, knowing thus, this three-day (rite) with the Saptadaça Stoma on both sides of the Viṣuvant, verily those sacrificers smite away evil from both worlds. They call them the Svarasāmans; by them the Atris rescued (_apaspṛṇvata_) the sun from the darkness; in that they rescued, therefore are they Svarasāmans. This is declared in a Ṛc,