Śatapatha Brāhmaṇa ("of a hundred paths") 14.2.1.9

14.2.1.9

atha vatsamupārjati pūṣāsītyayam vai pūṣā yoyam pavata eṣa hīdaṃ sarvam puṣyatyeṣa u pravargyastadetamevaitatprīṇāti tasmādāha pūṣāsīti

He then lets the calf to it (to suck), with, 'Pûshan thou art,'--Pûshan, doubtless, is he that blows here (the wind), for that one supports (push) all this (universe); and the Pravargya also is that (wind): it is him he thus pleases, and therefore he says, 'Pûshan thou art.'