Mbh 12.40.1a

"Vaisampayana said, 'Then Devaki's son Janardana of universal knowledge addressed king Yudhishthira who stood there with his brothers, saying, "In this world, O sire, Brahmanas are always the objects of worship with me. They are gods on earth having poison in their speech, and are exceedingly easy to gratify. Formerly, in the Krita age, O king, a Rakshasa of the name of Charvaka, O mighty-armed one, performed austere penances for many years in Vadari. Brahman repeatedly solicited him to ask for boons. At last the Rakshasa solicited the boon, O Bharata, of immunity from fear at the hand of every being in the universe. The Lord of the universe gave that high boon of immunity from fear at the hands of all creatures, subject to the only limitation that he should be careful of how he offended the Brahmanas. Having obtained that boon, the sinful and mighty Rakshasa of fierce deeds and great prowess began to give pain to the gods. The gods, persecuted by the might of the Rakshasa, assembling together, approached Brahman, for compassing their foe's destruction. The eternal and unchangeable god answered them, O Bharata, saying, 'I have already arranged the means by which the death of this Rakshasa may soon be brought about. There will be a king of the name of Duryodhana. Among men, he will be the friend of this wight. Bound by affection towards him, the Rakshasa will insult the Brahmanas. Stung by the wrong he will inflict upon them, the Brahmanas, whose might consists in speech, will in wrath censure him at which he will meet with destruction.' Even that Rakshasa Charvaka, O foremost of kings, slain by the curse of the Brahmanas, lies there deprived of life. Do not, O bull of Bharata's race, give way to grief. The kinsmen, O king, have all perished in the observance of Kshatriya duties. Those bulls among Kshatriyas, those high-souled heroes, have all gone to heaven. Do thou attend to thy duties now. O thou of unfading glory, let no grief be thine.