Mbh 7.194.3a

“‘Kripa said, “Placing Drona, that foremost of car-warriors, at our head, we commenced to fight with only the Panchalas. When the battle commenced, the Kurus and the Somakas, mingled together, roared at one another and began to strike down one another with their weapons. During the progress of that battle the Dhartarashtras began to be thinned. Seeing this, thy sire, filled with rage, invoked into existence a celestial weapon. Indeed, Drona, that bull among men, having invoked the Brahma weapon, slew his enemies with broad-headed arrows, by hundreds, and thousands.[256] Urged by fate, the Pandavas, the Kaikeyas, the Matsyas, and the Panchalas, O foremast of regenerate ones, approaching Drona’s car, began to perish. With his Brahma weapon, Drona despatched unto Yama’s abode a thousand brave warriors and two thousand elephants. Of a dark complexion, with his gray locks hanging down to his ears, and full five and eighty years old, the aged Drona used to careen in battle like a youth of sixteen, When the enemy’s troops were thus afflicted and the kings were being slain, the Panchalas, though filled with desire of revenge, turned back from the fight. When the enemy, turning back, partially lost their order, that vanquisher of foes, (viz., Drona), invoking celestial weapons into existence, shone resplendent like the risen sun. Indeed, thy valiant sire, getting into the midst of the Pandavas, and having arrows for the rays that emanated from him, resembled the midday sun at whom none could gaze. Scorched by Drona, as if by the blazing sun, they became cheerless and deprived of their energy and senses. Beholding them thus afflicted by Drona with his shafts, the slayer of Madhu, desirous of victory to the son of Pandu, said these words: ‘Truly, this foremost of all wielders of arms, this leader of the leaders is incapable of being vanquished in battle by the slayer of Vritra himself.