Mbh 3.201.2b

And, O king, having, obtained a boon from the Grandsire of all creatures, that Asura hath become incapable of being slain by the gods and Daityas and Rakshasas and Gandharvas. Slay though him, O king, and blessed be thou and let not thy heart turn to any other course. By slaying him thou wilt without doubt, achieve a great thing and thou wilt also obtain eternal and undying fame. And O king, when at the end of every year that wicked Asura lying covered with sands, wakes up and begins to breathe, then the whole earth with her mountains, forests and woods begins to tremble. And his breath raiseth up clouds of sands, and shroudeth the very sun, and for seven days continually the earth tremble all over, and sparks and flames of fire mixed with smoke spread far around and for all this, O king, I cannot rest in peace in my asylum. Slay thou him, O king, for the good of the world. Indeed, when that Asura is slain the triple world will be in peace and happiness. That thou art competent, O king, to slay that Asura, I fully believe. Thy energy will be enhanced by Vishnu with the addition of his own. In days of old, O king, Vishnu gave this boon that the king who should slay this fierce and great Asura would be pervaded by the invincible energy of Vishnu himself. Bearing that invincible Vaishnava energy in thyself, slay thou, O great king, that Daitya of fierce prowess. Possessed as Dhundhu is of mighty energy, no one, O king, that is endued with small energy himself will be capable of consuming him, even if he were to strive for a hundred years.’”