Mbh 7.181.2c

That Rakshasa was inimical to Brahmanas and sacrifices. Because he was a destroyer of sacrifices and of a sinful soul, therefore hath he been thus slain. O sinless one, by that act as a means, the dart given by Sakra, hath also been rendered futile. O son of Pandu, they that are destroyers of righteousness are all slayable by me. Even that is the vow made by me, for establishing righteousness. Whither the Vedas and truth and self-restraint and purity and righteousness and modesty and prosperity and wisdom and forgiveness are always to be met with, thither I myself always remain. Thou needst not be at all anxious about Karna’s slaughter. I will tell you the means by which you will slay him. Vrikodara also will succeed in slaying Suyodhana. I will tell thee, O son of Pandu, the means by which that will have to be compassed. Meanwhile, the uproar made by the hostile army is increasing. Thy troops also are flying away on all sides. Having achieved their objects, the Kauravas are destroying thy host. Indeed, Drona, that foremost of all smiters, is scorching us in battle.”’”