Mbh 7.188.2b

Thus resisted by Partha in the midst of all those illustrious warriors, Drona, struggling with vigour, cheerfully resisted Arjuna (in return), wondering all the while. Then the celestials and Gandharvas in thousands, and Rishis and bodies of Siddhas, were seen on all sides in the welkin. Filled with (those as also with) Apsaras and Yakshas and Rakshasas, it once more seemed that the welkin was darkened by gathering clouds. An invisible voice, fraught with the praises of Drona and the high-souled Partha, was heard to repeatedly course through the firmament. When in consequence of the weapons shot by Drona and Partha all sides seemed ablaze with light, the Siddhas and the Rishis that were present, said, “This is no human nor Asura, nor Rakshasa, nor celestial, nor Gandharva battle. Without doubt this is a high Brahma encounter. This battle is exceedingly beautiful and highly wonderful. We have never seen or heard of its like. Now, the preceptor prevails over the son of Pandu, and then the son of Pandu prevails over Drona. No one can find any difference between them. If Rudra, dividing his own self into two portions, fights, himself with himself, then may an instance be had to match this. Nowhere else can an instance be found to match it. Science, gathered in one place, exists in the preceptor; science and means are in the son of Pandu. Heroism, in one place, is in Drona; heroism and might are in the son of Pandu. None of these warriors can be withstood by foes in battle. If they wish, both of them can destroy the universe with the gods.” Beholding those two bulls among men, all invisible and visible creatures said these words. The high-souled Drona then, in that battle, invoked into existence the Brahma weapon, afflicting Partha and all invisible beings. Thereupon, the earth with the mountains and waters and trees trembled. Fierce winds began to blow. The seas swelled in agitation.