Mbh 12.36.1d

[117] It has been laid down that a Brahmana should acquire and practise the full measure of virtue. For a person at the kingly order it has been laid down that he should acquire and practise a measure of virtue less by a fourth part. So, a Vaisya should acquire a measure less (than a Kshatriya's) by a fourth and a Sudra less (than a Vaisya's) by a fourth. The heaviness or lightness of sins (for purposes of expiation) of each of the four orders, should be determined upon this principle. Having slain a bird or an animal, or cut down living trees, a person should publish his sin and fast for three nights. By having intercourse with one with whom intercourse is prohibited, the expiation for one is wandering in wet clothes and sleeping on a bed of ashes. These, O king, are the expiations for sinful acts, according to precedent and reason and scriptures and the ordinances. A Brahmana may be cleansed of all sins by reciting the Gayatri in a sacred place, all the while living upon frugal fare, casting off malice, abandoning wrath and hate, unmoved by praise and blame, and abstaining from speech. He should during the day-time be under shelter of the sky and should lie down at night even at such a place. Thrice during the day, and thrice during the night, he should also plunge with his clothes into a stream or lake for performing his ablutions. Observant of rigid vows, he should abstain from speech with women, Sudras, and fallen persons. A Brahmana by observing such regulations may be cleansed of all sins unconsciously committed by him. A person obtains in the other world the fruits, good or bad, of his acts here which are all witnessed by the elements. Be it virtue or be it vice, according to the true measure that one acquires of either, one enjoys or suffers the consequences (even here). By knowledge, by penances, and by righteous acts, therefore, one enhances his weal (even here). One, therefore may similarly enhance his misery by committing unrighteous acts.