B.G 3.08

नियतं कुरु कर्म त्वं कर्म ज्यायो ह्यकर्मणः। शरीरयात्रापि च ते न प्रसिद्ध्येदकर्मणः ॥८॥

niyataṁ kuru karma tvaṁ karma jyāyō hyakarmaṇaḥ। śarīrayātrāpi ca tē na prasiddhyēdakarmaṇaḥ ॥8॥

[नियतं कुरु कर्म त्वं कर्म ज्यायो हि अकर्मणः। शरीर यात्र अपि च ते न प्रसिद्ध्येत् अकर्मणः॥
niyataṁ = prescribed; kuru = do; karma = duties, actions; tvaṁ = you; karma = performing duties; jyāyō = is better; hi = certainly; akarmaṇaḥ = than abandoning duties; śarīra = bodily; yātra = maintenance; api = even; ca = and; tē = your; na = not; prasiddhyēt = is possible; akarmaṇaḥ = by abandonment of action;]

Do the prescribed duties, as performing one's duties is better than abandoning them. Even the maintenance of your body would not be possible by abandoning action.

Gīta Bhāshya 3.08

"niyatam karma" - prescribed duties as per one's occupation (varna) and stage (āshrama) in life.

अतः नियतं वर्णाश्रमोचितं कर्म कुरु ॥८॥

ataḥ niyataṁ varṇāśramōcitaṁ karma kuru ॥8॥

[ataḥ = therefore; niyataṁ = prescribed; varṇāśramōcitaṁ = in accordance with varna and āshrama; karma = actions, duties; kuru = perform;]

Therefore, perform the duties as prescribed by one's occupation (varna) and stage (āshrama) in life.