Mbh 6.42.3d

Hear now from me, O bull of Bharata’s race, of the three kinds of happiness. That in which one findeth pleasure from repetition (of enjoyment), which bringeth an end to pain, which is like poison first but resembleth nectar in the end, that happiness born of the serenity produced by a knowledge of self, is said to be of the quality of goodness.[306] That which is from the contact of the senses with their objects which resembleth nectar first but is like poison in the end, that happiness is held to be of the quality of passion. That happiness which in the beginning and its consequences deludeth the soul, and springeth from sleep, indolence, and stupidity, that is described to be of the quality of darkness. There is not, either on earth or heaven among the gods, the entity that is free from these three qualities born of nature. The duties of Brahmanas, Kshatriyas, and Vaisyas, and of Sudras also, O chastiser of foes, are distinguished by (these three) qualities born of nature. Tranquillity, self-restraint, ascetic austerities, purity, forgiveness, rectitude, knowledge, experience, and belief (in an existence hereafter),--these are the duties of Brahmanas, born of (their proper) nature. Bravery, energy, firmness, skill, not flying away from battle, liberality, the bearing of a ruler,--these are the duties of Kshatriyas, born of (their proper) nature. Agriculture, tending of cattle, and trade, are the natural duties of Vaisyas. Of Sudras also, the natural duty consists in servitude. Every man, engaged in his own duties, attains to perfection. Hear now how one obtains perfection by application to his duties. Him from whom are the movements of all beings, Him by whom all this is pervaded, worshipping him by (the performance of) one’s own duty, one obtaineth perfection. Better is one’s own duty though performed faultily than another’s duty well-performed. Performing the duty prescribed by (one’s own) nature, one incurreth no sin.