Krishna issues a direct, pragmatic command: 'niyataṃ kuru karma tvaṃ' (You must perform your prescribed duty). He provides two absolute reasons for this. First, a philosophical reason: action is inherently superior to inaction (karma jyāyo hy akarmaṇaḥ). Second, a brutally practical biological reason: without action, you couldn't even maintain your own physical body (śarīra-yātrāpi ca te na prasiddhyed).