Mbh 6.28.4a

“The Holy One said,--‘Many births of mine have passed away, O Arjuna, as also of thine. These all I know, but thou dost not, O chastiser of foes. Though (I am) unborn and of essence that knoweth no deterioration, though (I am) the lord of all creatures, still, relying on my own (material) nature I take birth by my own (powers) of illusion. Whenever, O Bharata, loss of piety and the rise of impiety occurreth, on those occasions do I create myself. For the protection of the righteous and for the destruction of the evil doers, for the sake of establishing Piety, I am born age after age. He who truly knoweth my divine birth and work to be such, casting off (his body) is not born again; (on the other hand) he cometh to me, O Arjuna. Many who have been freed from attachment, fear, wrath, who were full of me, and who relied on me, have, cleansed by knowledge and asceticism, attained to my essence. In whatsoever manner men come to me, in the selfsame manner do I accept them. It is my way, O Partha, that men follow on all sides.[169] Those in this world who are desirous of the success of action worship the gods, for in this world of men success resulting from action is soon attained. The quadruple division of castes was created by me according to the distinction of qualities and duties. Though I am the author thereof, (yet) know me to be not their author and undecaying.[170] Actions do not touch me. I have no longing for the fruits of actions. He that knoweth me thus is not impeded by actions. Knowing this, even men of old who were desirous of emancipation performed work. Therefore, do thou also perform work as was done by ancients of the remote past. What is action and what is inaction,--even the learned are perplexed at this. Therefore, I will tell thee about action (so that) knowing it thou mayst be freed from evil. One should have knowledge of action, and one should have knowledge of forbidden actions: one should also know of inaction.