Chapter 4 · Knowledge and Renunciation of Action · Krishna said
Bhagavad Gita 4.24 — Everything is Brahman
ब्रह्मार्पणं ब्रह्म हविर्ब्रह्माग्नौ ब्रह्मणा हुतम्। ब्रह्मैव तेन गन्तव्यं ब्रह्मकर्मसमाधिना ॥
brahmārpaṇaṃ brahma havirbrahmāgnau brahmaṇā hutam | brahmaiva tena gantavyaṃ brahmakarmasamādhinā ||
Meaning
The act of offering is Brahman, the offering is Brahman, it is offered by Brahman into the fire of Brahman. One who sees Brahman in every action reaches Brahman.