3.15

कर्म ब्रह्मोद्भवं विद्धि ब्रह्माक्षरसमुद्भवम् ।
तस्मात्सर्वगतं ब्रह्म नित्यं यज्ञे प्रतिष्ठितम् ॥

karma brahmodbhavaṃ viddhi brahmākṣarasamudbhavam
tasmāt sarvagataṃ brahma nityaṃ yajñe pratiṣṭhitam

śrībhagavān (श्रीभगवान्) is speaking, and he tells Arjuna (अर्जुन) to know the source of the action that 3.14 ended on.

The verse

Know action as arisen from brahma (ब्रह्म), and brahma (ब्रह्म) as arisen from the imperishable; therefore the all-pervading brahma (ब्रह्म) is always established in sacrifice.

नेपालीमा

कर्म ब्रह्मबाट उत्पन्न भएको जान, र ब्रह्म अविनाशीबाट उत्पन्न भएको जान। त्यसैले सर्वव्यापी ब्रह्म सधैँ यज्ञमा स्थापित छ।

Where it sits

3.14 stopped at sacrifice arising from action, and this verse puts a source under action, then seats that source in the sacrifice. 3.16 will say what a life is worth if the wheel is left unturned.

Split: कर्म + ब्रह्म-उद्भवम् + विद्धि + ब्रह्म + अक्षर-समुद्भवम् + तस्मात् + सर्व-गतम् + ब्रह्म + नित्यम् + यज्ञे + प्रतिष्ठितम्

karma + brahma-udbhavam + viddhi + brahma + akṣara-samudbhavam + tasmāt + sarva-gatam + brahma + nityam + yajñe + pratiṣṭhitam

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
कर्मkarmaaccusativeaction.
ब्रह्म-उद्भवम्brahma-udbhavamaccusativehaving its arising in brahma (ब्रह्म).
विद्धिviddhiimperative, 2nd singular of vid (विद्)know.
ब्रह्मbrahmaaccusative neuterbrahma (ब्रह्म), brahman. The same word is a name of the Veda.
अक्षर-समुद्भवम्akṣara-samudbhavamaccusativehaving its arising in the imperishable.
तस्मात्tasmātindeclinabletherefore.
सर्व-गतम्sarva-gatamnominative neutergone everywhere, all-pervading.
ब्रह्मbrahmanominative neuterbrahma (ब्रह्म) again.
नित्यम्nityamaccusative, adverbialalways.
यज्ञेyajñelocativein sacrifice.
प्रतिष्ठितम्pratiṣṭhitamnominative neuterestablished. Agrees with brahma (ब्रह्म).

The phrases

karma brahmodbhavam viddhi (कर्म ब्रह्मोद्भवम् विद्धि) is the first thing to know. Know action as arisen from brahma (ब्रह्म). अ + उ a + u inside the compound is o (ओ): ब्रह्म + उद्भव brahma + udbhava.

brahma akṣarasamudbhavam (ब्रह्म अक्षरसमुद्भवम्) is the second object of the same verb. Know brahma (ब्रह्म) as arisen from the imperishable. अ + अ a + a across the two words is ā (आ): brahmākṣara (ब्रह्माक्षर).

tasmāt sarvagatam brahma nityam yajñe pratiṣṭhitam (तस्मात् सर्वगतम् ब्रह्म नित्यम् यज्ञे प्रतिष्ठितम्) is why the wheel is not a human invention. Therefore the all-pervading brahma (ब्रह्म) stands always in the sacrifice.

Sanskrit in this line

अ + उ a + u becomes o (ओ). ब्रह्म + उद्भव brahma + udbhava is brahmodbhava (ब्रह्मोद्भव). The same join makes purovāca (पुरोवाच) in 3.10, from पुरा + उवाच purā + uvāca, except there the first vowel was already long, and आ + उ ā + u is also o (ओ). Short or long a (अ) / ā (आ), plus u (उ), gives o (ओ).

Say it back

Three steps: action from brahma (ब्रह्म), brahma (ब्रह्म) from the imperishable, brahma (ब्रह्म) standing in the sacrifice. If yajñe (यज्ञे) falls off the end, you have a cosmology and not this verse.