Mahabharata Bhishma Parva Chapter 52:4

Mahabharata Bhishma Parva (Bhagavat-Gita Parva) Chapter 52:4 And those mighty car-warriors twang their bows, both in the same manner. And with the blare of their conches and the rattle of their car-wheels, the very Earth was suddenly rent. And it began to tremble and produce subterranean noises. And nobody, O bull of Bharata's race, could detect any latches in either of them. Both of them was possessed of great might and great courage in battle, each was other's match. And by (the sight of) his standard alone, the Kauravas could approach him (for aid). And so the Pandavas approached Pritha's son (for aid), guided by his standard only. And beholding, O king, prowess thus displayed by those two foremost of men, O Bharata, all creatures (present) in that battle were filled with wonder. And none, O Bharata, observed any difference between the two, just as none finds any transgression in a person observant of morality. And both of them (at times) became perfectly invisible in consequence of clouds of arrows. And soon enough both of them in that battle became visible. And the gods with Gandharvas and the Charanas, and the great Rishis beholding their prowess, said unto one another, 'These mighty car-warriors when excited with rage, are incapable of ever being vanquished in battle by all the worlds with the gods, the Asuras and the Gandharvas. This highly wonderful battle would be wonderful in all the worlds. Indeed, a battle such as this will never take place again. Bhishma is incapable of being conquered in combat by Pritha's son of great intelligence, showering his arrows in battle, with bow and car and steeds. So also that great bowman, the son of Pandu, incapable of being vanquished in battle by the very gods, Bhishma is not competent to conquer in combat. As long as the world itself will last, so long will this battle continue equally.' We heard these words, O king, fraught with the praise of Ganga's son and Arjuna in battle bruited about there. And while those two were engaged in displaying their prowess, other warriors of thy side and of the Pandavas, O Bharata, slew one another in battle, with sharp-edged scimitars, and polished battle-axes, and innumerable arrows, and diverse kinds of weapons. And the brave combatants of both armies cut one another down, while that terrible and murderous conflict lasted. And the encounter also, O king, that took place between Drona and the prince of the Panchalas, was awful.