Mbh 1.230.2b

Then, O monarch, he of a hundred sacrifices (Indra), beholding the immortals retreat, became filled with joy and applauded Krishna and Arjuna. And when the celestials gave up the fight, an incorporeal voice, deep and loud, addressing him of a hundred sacrifices, said, ‘Thy friend Takshaka, that chief of snakes, hath not been slain! Before the conflagration commenced in Khandava he had journeyed to Kurukshetra. Know from my words, O Vasava, that Vasudeva and Arjuna are incapable of being vanquished in battle by any one! They are Nara and Narayana--those gods of old heard of in heaven! Thou knowest what their energy is and what their prowess. Invincible in battle, these best of old Rishis are unconquerable by any one in all the worlds! They deserve the most reverential worship of all the celestials and Asuras; of Yakshas and Rakshasas and Gandharvas, of human beings and Kinnaras and Nagas. Therefore, O Vasava, it behoveth thee to go hence with all the celestials. The destruction of Khandava hath been ordained by Fate!’ Then the chief of the immortals, ascertaining those words to be true abandoned his wrath and jealousy, and went back to heaven. The dwellers in heaven, O monarch, beholding the illustrious Indra abandon the fight, followed him with all their soldiers. Then those heroes, Vasudeva and Arjuna, when they saw the chief of the celestials retreat accompanied by all the gods, set up a leonine roar. And, O monarch, Kesava and Arjuna, after Indra had left the scene, became exceedingly glad. Those heroes then fearlessly assisted at the conflagration of the forest. Arjuna scattered the celestials like the wind scattering the clouds, and slew with showers of his arrows, numberless creatures that dwelt in Khandava. Cut off by Arjuna’s arrows, no one amongst the innumerable creatures could escape from the burning forest. Far from fighting with him, none amongst even the strongest creatures mustered there could look at Arjuna whose weapons were never futile.