Mbh 7.191.1b

Let some man, therefore, tell him that Aswatthaman hath been slain in battle.” This advice, however, O king was not approved by Kunti’s son, Dhananjaya. Others approved of it. But Yudhishthira accepted it with great difficulty. Then the mighty-armed Bhima, O king, slew with a mace a foe-crushing, terrible and huge elephant named Aswatthaman, of his own army, belonging to Indravarman, the chief of the Malavas. Approaching Drona then in that battle with some bashfulness Bhimasena began to exclaim aloud, “Aswatthaman hath been slain.” That elephant named Aswatthaman having been thus slain, Bhima spoke of Aswatthaman’s slaughter. Keeping the true fact within his mind, he said what was untrue. Hearing those highly disagreeable words of Bhima and reflecting upon them, Drona’s limbs seemed to dissolve like sands in water. Recollecting however, the prowess of his son, he soon came to regard that intelligence as false. Hearing, therefore, of his slaughter, Drona did not become unmanned. Indeed, soon recovering his senses, he became comforted, remembering that his son was incapable of being resisted by foes. Rushing towards the son of Prishata and desirous of slaying that hero who had been ordained as his slayer, he covered him with a thousand keen shafts, equipped with kanka feathers. Then twenty thousand Panchala car-warriors of great energy covered him, while he was thus careering in battle, with their shafts. Completely shrouded with those shafts, we could not any longer see that great car-warrior who then resembled, O monarch, the sun, covered with clouds in the season of rains. Filled with wrath and desirous of compassing the destruction of those brave Panchalas, that mighty car-warrior, that scorcher of foes, viz., Drona, dispelling all those shafts of the Panchalas, then invoked into existence the Brahma weapon. At that time, Drona looked resplendent like a smokeless, blazing fire.