Brahmārpañam Brahma Havir
BrahmāgnauBrahmañāhutaṃ,

Brahmaiva Tena Gantavyam
BrahmakarmāSamādhinah.

The act of offering is God. The oblation is God. By God it is offered into the Fire of God.
God is That which is to be attained by him who performs action pertaining to God.