Chapter IV · Śloka 24
ब्रह्मार्पणं ब्रह्म हविर्ब्रह्माग्नौ ब्रह्मणा हुतम् |
ब्रह्मैव तेन गन्तव्यं ब्रह्मकर्मसमाधिना ||
ब्रह्मैव तेन गन्तव्यं ब्रह्मकर्मसमाधिना ||
brahmārpaṇaṃ brahma havir brahmāgnau brahmaṇā hutam |
brahmaiva tena gantavyaṃ brahma-karma-samādhinā ||
brahmaiva tena gantavyaṃ brahma-karma-samādhinā ||
The act of offering is Brahman, the oblation is Brahman, offered by Brahman into the fire of Brahman — Brahman alone is to be reached by one absorbed in Brahman through action.
The most celebrated verse of this chapter dissolves all dualities within the sacrificial act: instrument, substance, fire, and offerer are all Brahman. For the one who sees this, every act of living is already worship.