Know that action (karma) arises from Brahman, and Brahman arises from the Imperishable (akṣara). Therefore, the all-pervading Brahman is eternally established in sacrifice (yajña).
Action comes from the spirit of prayer, whose source is OM, sound of the imperishable; so the pervading infinite spirit is ever present in rites of sacrifice.
(15) From Brahman work arises, know this, and Brahman is born from the Imperishable; therefore is Brahman, penetrating everywhere, forever based on sacrifice.
3.15 Know that action has the veda as its origin; the Vedas has the Immutable as its source. Hence, the all-pervading Veda is forever based on sacrifice.
3.15 Know that activity springs from 'Brahman', i.e., the physical body, 'Brahman' arises from the imperishable (self); therefore the all-pervading 'Brahman' is ever established in sacrifice.
3.15 Know thou that action comes from Brahma and Brahma comes from the Imperishable. Therefore, the all-pervading (Brahma) ever rests in sacrifice.