Śatapatha Brāhmaṇa ("of a hundred paths") 3.1.4.9

3.1.4.9

sarasvatyai pūṣṇe 'gnaye svāheti | vāgvai sarasvatī vāgyajñaḥ paśavo vai pūṣā puṣṭirvai pūṣā puṣṭiḥ paśavaḥ paśavo hi yajñastadyadevātra yajñasya tadevaitatsambhṛtyātmankurute

'To Sarasvatî, to Pûshan, to Agni, hail!' Now Sarasvatî is speech, and the sacrifice also is speech. And Pûshan represents cattle, because Pûshan means prosperity (pushti), and cattle also means prosperity, since the sacrifice means cattle. What part of the sacrifice (is contained) in this (third libation), that he now collects and makes his own.