Shatapatha Brahmana 8.5.1.12

8.5.1.12

atha madhye | agneḥ purīṣamasīti brahma vai caturthī citiragniru vai brahma tasyā etatpurīṣamiva yatpañcamyapso nāmeti tasyokto bandhuḥ

Then in the middle (the fifth), with, 'Agni's soil-cover thou art!'--the fourth layer indeed is the Brahman, and the Brahman is Agni, and this, the fifth layer is, as it were, the (soil-)cover of that (fourth layer);--'his sap, in truth: may the All-gods sing thy praises! Seat thee here, laden with Stomas, and rich in fat! Gain for us, by sacrifice, wealth with offspring!' as the text so the sense.