Mbh 12.33.3b

Although this entanglement of thy heart is a mere delusion, still, if it pleaseth thee, O king, perform expiatory rites (for washing thyself free of thy so-called sin). It is heard, O Partha, that the gods and the Asuras fought against each other. The Asuras were the elder, and the gods the younger brothers. Covetous of prosperity, fierce was the battle fought between them. The fight lasted for two and thirty thousand years. Making the earth one vast expanse of blood, the gods slew the Daityas and gained possession of heaven. Having obtained possession of the earth, a (large) number of Brahmanas, conversant with the Vedas, armed themselves, stupefied with pride, with the Danavas for giving them help in the fight. They were known by the name of Salavrika and numbered eight and eighty thousand. All of them, however, were slain by the gods. Those wicked-souled persons who desire the extinction of virtue and who set sinfulness agoing deserve to be slain even as the furious Daityas were slain by the gods. If by slaying a single individual a family may be saved, or, if by slaying a single family the whole kingdom may be saved, such an act of slaughter will not be a transgression. Sin, O king, sometimes assumes the form of virtue, and virtue sometimes assumes the form of sin. They, however, that are learned, know which is which. Therefore, console thyself, O son of Pandu, for thou art well versed in the scriptures. Thou hast, O Bharata, only followed the path formerly trodden by the very gods. Men like yourselves never go to hell, O bull of Pandu's race! Comfort these thy brothers and all thy friends, O scorcher of foes! He who deliberately engages himself in sinful acts, and committing sinful acts feels no shame but continues the same as before, is called (in the scripture) a great sinner. There is no expiation for him and his sins know no diminution. Thou art born in noble race.