Mbh 7.142.2a

“‘Bhurisravas said, “Thou hast, O son of Kunti, done a cruel and heartless deed, since without being engaged with me, thou hast, unseen by me, cut off my arm. Shalt thou not have to say unto Yudhishthira, the royal son of Dharma, even this, viz., ‘Bhurisravas, while otherwise engaged, was slain by me in battle?’ Wert thou taught this use of weapons by the high-souled Indra or by Rudra, O Partha, or by Drona, or by Kripa? Thou art, in this world, better acquainted with the rules about the use of weapons than all others. Why then hast thou cut off in battle the arm of a warrior who was not engaged with thee? The righteous never strike him that is heedless, or him that is terrified, or him that is made carless, or him that beggeth for life or protection, or him that hath fallen into distress. Why, then, O Partha, hast thou perpetrated such an extremely unworthy deed that is sinful, that is worthy only of a low wretch, and that is practised by only a wicked bloke! A respectable person, O Dhananjaya, can easily accomplish a deed that is respectable. A deed, however, that is disrespectable becomes difficult of accomplishment by a person that is respectable. A man quickly catches the behaviour of those with whom and amongst whom he moves. This is seen in thee, O Partha! Being of royal lineage and born, especially, in Kuru’s race, how hast thou fallen off from the duties of a Kshatriya, although thou wert of good behaviour and observant of excellent vows. This mean act that thou hast perpetrated for the sake of the Vrishni warrior, is without doubt, conformable to Vasudeva’s counsels. Such an act does not suit one like thee. Who else, unless he were a friend of Krishna’s, would inflict such a wrong upon one that is heedlessly engaged with another in battle? The Vrishnis and the Andhakas are bad Kshatriyas, ever engaged in sinful deeds, and are, by nature, addicted to disreputable behaviour. Why, O Partha, hast thou taken them as model?”