Mahabharata Bhishma Parva Chapter 50:2

Mahabharata Bhishma Parva (Bhagavat-Gita Parva) Chapter 50:2 The celestial weapons of Bhishma and the high-souled Drona, incessantly applied, are consuming all the Kshatriyas. O Krishna, such is his prowess, that Bhishma, with wrath excited, aided by the kings (on his side), will, without doubt annihilate us. O Lord of Yoga, look for that great bowman, that mighty car-warrior, who will give Bhishma his quietus like rain-charged clouds quenching a forest conflagration. (Then) through thy grace, O Govinda, the son of Pandu, their foes being slain, will, after recovery of their kingdom, be happy with their kinsmen. Having said this, the high-souled son of Pritha, with heart afflicted by grief and mind turned within, remained silent for a long while in a reflected mood. Beholding the son of Pandu stricken with grief and deprived of his senses by sorrow, Govinda then gladdening all the Pandavas said, 'Do not grieve, O chief of the Bharatas. It behoveth thee not to grieve, when thy brothers are all heroes and renowned bowmen in the world. I also am employed in doing thee good, as also that mighty car-warrior Satyaki and Virata and Drupada, both reverend in years, and Dhrishtadyumna of Prishata's line. And so also, O best of kings, all these monarchs with their (respective) troops are expectant of thy favour and devoted to thee, O king. This mighty car-warrior Dhrishtadyumna of Prishata's race placed in command of thy army is always desirous of thy welfare and engaged in doing that which is agreeable to thee, as also this Sikhandin, O thou of mighty arms, who is certainly the slayer of Bhishma.' Hearing these words, the king (Yudhishthira), said, unto that mighty car-warrior Dhrishtadyumna, in that very assembly and in the hearing of Vasudeva, these words, 'O Dhrishtadyumna, mark these words that I say unto thee, O thou of Prishata's line. The words uttered by me should not be transgressed. Approved by Vasudeva, thou hast been the commander of our forces. As Kartikeya, in days of old, was ever the commander of the celestial host, so also art thou, O bull among men, the commander of the Pandava host. Putting forth thy prowess, O tiger among men, slay the Kauravas. I will follow thee, and Bhima, and Krishna also, O sire, and the sons of Madri united together, and the sons of Draupadi accoutred in mail, and all the other foremost of kings, O bull among men.' Then gladdening (the listeners) Dhrishtadyumna said, 'Ordained of old by Sambhu himself, I am, O son of Pritha, the slayer of Drona. I shall now fight in battle against Bhishma, and Drona and Kripa and Salya and Jayadratha and all the proud monarchs (on the Kuru side)'. When that foremost of princes, that slayer of foes, the son of Prishata, said this defiantly, the Pandava warriors, endued with great energy and incapable of being defeated in battle, all set up a loud shout.