Mbh 7.124.1a

“Sanjaya said, ‘In the afternoon of that day, O king, a dreadful battle, characterised by roars, deep as those of the clouds, once more occurred between Drona and the Somakas. That foremost of men, Drona, mounted on his car of red steeds, and intent on battle rushed against the Pandavas, with moderate speed. The valiant son of Bharadwaja, that great bowman endued with mighty strength, that hero born in an excellent pot, engaged in doing what was agreeable to thee, O king, and striking down, O Bharata, many foremost of warriors with his whetted arrows, equipped with beautiful wings, seemed to sport in that battle. Then that mighty car-warrior of the Kaikeyas, Vrihatkshatra, irresistible in battle, and the eldest of five brothers, rushed against him. Shooting many keen shafts, he greatly afflicted the preceptor, like a mighty mass of clouds pouring torrents of rain on the mountain of Gandhamadana. Then Drona, O king, excited with wrath sped at him five and ten shafts whetted on stone and equipped with wings of gold. The prince of the Kekayas, however, cheerfully cut off every one of those shafts shot by Drona, and which resembled angry snakes of virulent poison, with five shafts of his own. Beholding that lightness of hand displayed by him that bull among Brahmanas, then, sped at him eight straight shafts. Seeing those shafts shot from Drona’s bow, swiftly coursing towards him, Vrihatkshatra in that battle resisted them with as many sharp shafts of his. Beholding that exceedingly difficult feat achieved by Vrihatkshatra, thy troops, O king, were filled with amazement. Then Drona, O monarch, applauding Vrihatkshatra, invoked into existence the irresistible and celestial weapon called Brahma in that battle. The prince of the Kekayas, seeing it shot by Drona in battle, baffled that Brahma weapon, O monarch, by a Brahma weapon of his own.