Mbh 7.27.2c

Hear, O Partha, what that boon was. ‘Possessed of the Vaishnava weapon, let my son become incapable of being slain by the gods and the Asuras. It behoveth thee to grant me that weapon.’ Hearing this prayer, I then gave, in days of old, the supreme and infallible Vaishnava weapon to the Earth’s son. I said also at that time these words, ‘O Earth, let this weapon be infallible for the protection of Naraka. None will be able to slay him. Protected by this weapon, thy son will always, in all the worlds, be invincible and crush all hostile hosts.’ Saying, So be it! the intelligent goddess went away, her wishes fulfilled. And Naraka also became invincible and always scorched his foes. It was from Naraka, O Partha, that the ruler of the Pragjyotishas got this weapon of mine. There is none, in all the world, O sire, including even Indra and Rudra, who is unslayable by this weapon. It was for thy sake, therefore, that I baffled it, violating my promise. The great Asura hath now been divested of that supreme weapon. Slay now, O Partha, that invincible foe of thine, viz., Bhagadatta, enemy of the gods, even as I formerly slew for the good of the worlds, the Asura Naraka.” Thus addressed by the high-souled Kesava, Partha suddenly overwhelmed Bhagadatta with clouds of whetted arrows. Then, the mighty-armed and high-souled Arjuna fearlessly struck a long arrow between the frontal globes of his enemy’s elephant. That arrow, splitting the elephant like the thunder splitting a mountain, penetrated into its body to the very wings, like a snake penetrating into an ant-hill. Though urged repeatedly then by Bhagadatta, the elephant refused to obey like a poor man’s wife her lord. With limbs paralysed, it fell down, striking the earth with its tusks. Uttering a cry of distress, that huge elephant gave up the ghost. The son of Pandu then, with a straight shaft furnished with a crescent-shaped head, pierced the bosom of king Bhagadatta.