Mbh 7.151.2a

“‘Karna said, “Do not blame the preceptor. That Brahmana is fighting according to the measure of his power and courage and regardless of his very life. If Arjuna, of white steeds, having transgressed him, penetrated into our array, the slightest fault does not, for that, attach to the preceptor. Phalguna is accomplished in weapons, possessed of great activity, endued with youth; he is a hero who has mastered all arms; he is distinguished for the celerity of his movements. Armed with celestial weapons and mounted on his ape-bannered car, the reins of whose steeds again were in the hands of Krishna, cased in impenetrable armour, and taking his celestial bow Gandiva of unfading might, the valiant Arjuna, scattering keen arrows, and proud of the strength of his arms, transgressed Drona. There is nothing to wonder at this. The preceptor, on the other hand is, O king, old and incapable of proceeding quickly. He is also, O king, incapable of exercising his arms long. It was for this that Phalguna, of white steeds and having Krishna for his charioteer, succeeded in transgressing the preceptor. For this reason also, I do not see any fault in Drona. For all that, when Arjuna, of white steeds, penetrated into our array, having transgressed the preceptor it seems that the latter, however skilled in weapons, is incapable of vanquishing the Pandavas in battle. I think that which is ordained by Fate never occurs otherwise. And since, O Suyodhana, in spite of ourselves fighting to the utmost extent of our powers, the ruler of the Sindhus has been slain in battle, it seems that Fate is all-powerful. With thyself we had all been exerting to the utmost of our might on the field of battle. Fate, however, baffling our exertions, did not smile on us. We have always exerted to injure the Pandavas, relying both on deceit and prowess. Whatever act, O king, a person afflicted by Fate does, is frustrated by Fate, however, much the person himself may strive to achieve it.