Shatapatha Brahmana 14.3.2.25

14.3.2.25

yajamāno vai pravargyaḥ tasyātmā prajā paśavaḥ sarvam vai yajamānaḥ sarvam pravargyaḥ sa yatpravṛktastadātmā yadrucitastatprajā yatpinvitastatpaśavo yadā vai paśavaḥ pinvate'thaināntsarve devāḥ sarvāṇi bhūtānyupajīvanti pinvante ha vā asmai paśavo ya evametadveda

The Pravargya, indeed, is the Sacrificer, his own self, his offspring (or people) and cattle; for the Sacrificer is everything, and the Pravargya is everything when it is placed on the fire then it is his own self; when it is burning-hot then it is his offspring; and when it flows over then it is his cattle;--but, indeed, when the cattle overflow (with milk) all the gods and all beings subsist thereon; and, verily, the cattle overflow for him who thus knows this.