Mbh 7.195.1a

“Dhritarashtra said, ‘Hearing, O Sanjaya, of the slaughter, by unrighteous means, of his aged sire, by Dhrishtadyumna, what did the valiant Aswatthaman say, he, that is, in whom human and Varuna and Agneya and Brahma and Aindra and Narayana weapons are always present? Indeed, learning that the preceptor, that foremost of virtuous men, had been unrighteously slain by Dhrishtadyumna in battle, what did Aswatthaman say? The high-souled Drona, having obtained the science of weapons from Rama have imparted (a knowledge of) all the celestial weapons unto his son desirous of seeing the latter adorned with all the accomplishments (of a warrior). There is only one person in this world, viz., the son, and none else, whom people desire to become superior to themselves. All high-souled preceptors have this characteristic, viz., that they impart all the mysteries of their science unto either sons or devoted disciples. Becoming his sire’s pupil, O Sanjaya, and obtaining all those mysteries with every detail, the son of Saradwat’s daughter has become a second Drona, and a great hero. Aswatthaman is equal to Karna in knowledge of weapons, to Purandara in battle, to Kartavirya in energy, and Vrihaspati in wisdom. In fortitude, that youth is equal to a mountain, and in energy to fire. In gravity, he is equal to an ocean, and in wrath, to the poison of the snake. He is the foremost of all car-warriors in battle, a firm bowman, and above all fatigue. In speed he is equal to the wind itself and he careens in the thick of fight like Yama in rage. While his engaged in shooting arrows in battle, the very earth becomes afflicted. Of prowess incapable of being baffled, that hero is never fatigued by exertions. Purified by the Vedas and by vows, he is a thorough master of the science of arms, like Rama, the son of Dasaratha. He is like the ocean, incapable of being agitated.