Mbh 12.37.2a

"'Vyasa said, "In this connection is cited the old account of a discourse between the ascetics and that lord of creation, viz., Manu. In the Krita age, an assembly of Rishis, of rigid vows, having approached the great and puissant lord of creation, Manu, while seated at his ease, solicited him to discourse on duties, saying, 'What food should be taken, who is to be regarded a deserving person (for gifts), what gifts should be made, how should a person study, and what penances should one perform and how, and what acts should be done and what acts should not be done, O lord of creation, tell us everything about all this.' Thus addressed by them, the divine and self-born Manu said unto them, 'Listen to me as I expound the duties in brief and in detail. In regions which have not been interdicted, silent recitation (of sacred mantras, homa), fasts, knowledge of self, sacred rivers, regions inhabited by men devoted to this pious acts,--these have been laid down as acts and objects that are cleansing. Certain mountains also are cleansing, as also the eating of gold and bathing in waters into which have been dipped gems and precious stones. Sojourn to holy places, and eating of sanctified butter--these also, without doubt speedily cleanse a man. No man would ever be called wise if he is indulged in pride. If he wishes to be long-lived, he should for three nights drink hot water (as an expiation for having indulged in pride). Refusal to appropriate what is not given, gift, study (of scriptures), penance, abstention from injury, truth, freedom from wrath, and worship of the gods in sacrifices,--these are the characteristics of virtue. That again which is virtue may, according to time and place, be sin. Thus appropriation (of what belongs to others), untruth, and injury and killing, may under special circumstances, become virtue. With respect to persons capable of judging, acts are of two kinds, viz., virtuous and sinful.