3.9

यज्ञार्थात्कर्मणोऽन्यत्र लोकोऽयं कर्मबन्धनः ।
तदर्थं कर्म कौन्तेय मुक्तसङ्गः समाचर ॥

yajñārthāt karmaṇo 'nyatra loko 'yaṃ karmabandhanaḥ
tad-arthaṃ karma kaunteya muktasaṅgaḥ samācara

śrībhagavān (श्रीभगवान्) is speaking, and the command of 3.8 now gets its aim.

The verse

Other than action done for sacrifice, this world is bound by action; for that purpose, son of Kuntī (कुन्ती), perform action, free of attachment.

नेपालीमा

यज्ञका लागि गरिएको कर्मबाहेक यो लोक कर्मले बाँधिन्छ। त्यसैका लागि, हे कुन्तीका छोरा, आसक्ति छाडेर कर्म गर।

Where it sits

3.8 said to do the appointed action, and this verse says what keeps it from being a bond: it is done for yajña (यज्ञ), and the doer is not stuck to it. The next verses tell how that sacrifice was set up.

Split: यज्ञ-अर्थात् + कर्मणः + अन्यत्र + लोकः + अयम् + कर्म-बन्धनः + तत्-अर्थम् + कर्म + कौन्तेय + मुक्त-सङ्गः + समाचर

yajña-arthāt + karmaṇaḥ + anyatra + lokaḥ + ayam + karma-bandhanaḥ + tat-artham + karma + kaunteya + mukta-saṅgaḥ + samācara

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
यज्ञ-अर्थात्yajña-arthātablativethan for the sake of sacrifice. artha (अर्थ) here is the purpose.
कर्मणःkarmaṇaḥablativethan action. With yajñārthāt (यज्ञार्थात्), action whose purpose is the sacrifice.
अन्यत्रanyatraindeclinableelsewhere, otherwise.
लोकःlokaḥnominativethe world.
अयम्ayamnominative masculinethis.
कर्म-बन्धनःkarma-bandhanaḥnominativebound by action. Its binding is action.
तत्-अर्थम्tat-arthamaccusative, adverbialfor the sake of that. That is the sacrifice.
कर्मkarmaaccusativeaction.
कौन्तेयkaunteyavocativeson of Kuntī (कुन्ती). Arjuna (अर्जुन).
मुक्त-सङ्गःmukta-saṅgaḥnominativeone whose attachment is released.
समाचरsamācaraimperative, 2nd singular of सम्-आ-चर् sam-ā-carperform.

The phrases

yajñārthāt karmaṇo 'nyatra (यज्ञार्थात् कर्मणो ऽन्यत्र) is the exception and everything outside it. Other than action done for the sacrifice. कर्मणः + अन्यत्र karmaṇaḥ + anyatra is karmaṇo 'nyatra (कर्मणोऽन्यत्र).

loko 'yaṃ karmabandhanaḥ (लोको ऽयं कर्मबन्धनः) is what the world is, outside that exception. This world is action's binding. लोकः + अयम् lokaḥ + ayam is loko 'yam (लोकोऽयम्).

tad-artham karma kaunteya muktasaṅgaḥ samācara (तदर्थम् कर्म कौन्तेय मुक्तसङ्गः समाचर) is the command with its manner. For that purpose, perform action, as one whose clinging has been released. muktasaṅgaḥ (मुक्तसङ्गः) is nominative, describing the man who is told to act.

Sanskrit in this line

anyatra (अन्यत्र) takes the ablative of the thing one is elsewhere than. yajñārthāt karmaṇaḥ (यज्ञार्थात् कर्मणः) is that ablative. "Elsewhere than action for the sacrifice." The same case that meant "than" with a comparative in 3.1 means "other than" with anyatra (अन्यत्र).

Say it back

Say what kind of action binds, and the two words he must carry into the act: for the sacrifice, and unattached. If muktasaṅgaḥ (मुक्तसङ्गः) drops out, the verse has become "work for a reward."