Shatapatha Brahmana 1.1.3.6

1.1.3.6

sa utpunāti | saviturvaḥ prasava utpunāmyacidreṇa pavitreṇa sūryasya raśmibhiriti savitā vai devānām prasavitā tatsavitṛprasūta evaitadutpunātyacidreṇa pavitreṇeti yo vā ayam pavata eṣo 'cidram pavitrametenaitadāha sūryasya raśmibhirityete vā utpavitāro yatsūryasya raśmayastasmādāha sūryasya raśmibhiriti

He strains it, with the text (Vâg. S. I, 12 b) 'By the impulse of Savitri I purify thee with this flawless purifier (or ventilator, pavitra), with the rays of the sun!' For Savitri is the impeller (prasavitri) of the gods, so that he strains this (water) as one impelled by Savitri. 'With this flawless purifier (ventilator, pavitra),' he says, because this (wind) which here ventilates (or purifies, pavate) is a flawless purifier. 'With the rays of the sun,' he says, because they, the rays of the sun, are certainly purifying; and for this reason he says, 'With the rays of the sun.'