The Great Epic of the Bhārata dynasty 7.168.31

7.168.31

vidharmiṇaṃ dharmavidbhiḥ proktaṃ teṣāṃ viṣopamam |
jānandharmārthatattvajñaḥ kimarjuna vigarhase || 31 ||

Professing himself to be a Brahmana, he was in the habit of using irresistible illusion. By an illusion itself hath he been slain today. O Partha, what is there that is improper in this? Drona having been thus punished by me, if his son, from rage, uttereth loud roars, what do you lose by that? I do not think it at all wonderful that Drona's son, urging the Kauravas to battle, will cause them to be slain, unable to protect them himself. Thou art acquainted with morality. Why then dost thou say that I am a slayer of my preceptor? It was for this that I was born as a son to the king of the Panchalas, having sprung from the (sacrificial) fire. How, O Dhananjaya, you call him a Brahmana or Kshatriya, with whom, while engaged in battle, all acts, proper and improper, were the same? O foremost of men, why should not he be slain, by any means in our power, who, deprived of his senses in wrath, used to slay with the Brahma weapons even those that were unacquainted with weapons? He that is unrighteous is said by those that are righteous to be equal to poison. Knowing this, [paragraph continues] O thou that art well versed with the truths of morality, why dost thou, O Arjuna, reproach me? That cruel car-warrior was seized and slain by me. I have done nothing that is worthy of reproach. Why then, O Vibhatsu, dost thou not congratulate me? O Partha, I have cut off that terrible head, like unto the blazing sun or virulent poison or the all-destroying Yuga fire, of Drona.