Śatapatha Brāhmaṇa ("of a hundred paths") 9.5.2.4

9.5.2.4

vārtrahatyāya śavase | sahadānum puruhūta kṣiyantamiti vārtraghnībhyām prathamābhyāmupatiṣṭata etadvai devā vṛtram pāpmānaṃ hatvāpahatapāpmāna etatkarmākurvata tathaivaitadyajamāno vṛtram pāpmānaṃ hatvāpahatapāpmaitatkarma kurute

[He approaches reverently the fire-altar, with, Vâg. S. XVIII, 68-74], 'For mighty strength that smiteth Vritra, and for victory in battle, we call thee hither, O Indra!' 'O much-invoked Indra, crush thou the handless Kunâru, lurking here, together with the Dânus; and with might smite thou the footless Vritra, the ever-growing mocker!' thus he reverently stands by (the fire) with the first two (verses) relating to the slaying of Vritra. For now the gods, having warded off Vritra, evil, performed this rite freed from evil; and in like manner does the Sacrificer, having warded off Vritra, evil, now perform this rite freed from evil.