Mbh 6.42.3e

One must not abandon, O son of Kunti, one’s natural duty though tainted with evil, for all actions are enveloped by evil like fire by smoke. He whose mind is unattached everywhere, who hath subdued his self, and whose desire hath departed, obtaineth, through renunciation, the supreme perfection of freedom from work. Learn from me, only in brief, O son of Kunti, how one, having obtained (this kind of) perfection, attaineth to Brahma which is the supreme end of knowledge. Endued with a pure mind, and restraining his self by constancy, renouncing sound and other objects of sense, and casting off affection and aversion, he who resideth in a lonely place, eateth little, and restraineth speech, body, and mind, who is ever intent on meditation and abstraction, who hath recourse to indifference, who, abandoning egoism, violence, pride, lust, wrath, and (all) surroundings, hath been freed from selfishness and is tranquil (in mind), becometh fit for assimilation with Brahma. Becoming one with Brahma, tranquil in spirit, (such a) one grieveth not, desireth not; alike to all beings, he obtaineth the highest devotion to Me. By (that) devotion he truly understandeth Me. What I am, and who I am; then understanding Me truly, he entereth into Me forthwith. Even performing all actions at all times having refuge in Me, he obtaineth, through my favour, the seat that is eternal and imperishable. Dedicating in thy heart all actions to Me, being devoted to Me, resorting to mental abstraction, fix thy thoughts constantly on Me. Fixing thy thoughts on Me, thou wilt surmount all difficulties through my grace. But if from self-conceit thou wilt not listen, thou wilt (then) utterly perish. If, having recourse to self-conceit, thou thinkest--I will not fight,--that resolution of thine would be vain, (for) Nature will constrain thee. That which, from delusion, thou dost not wish to do, thou wilt do involuntarily, bound by thy own duty springing from (thy own) nature.