Obligation of Jihad
Jabir bin 'Abdullah (May Allah be pleased with them) reported: The dead body of my father, who was mutilated by the enemy, was brought and placed before the Prophet صلى الله عليه وسلم. I got up to uncover his face but the people stopped me, and the Prophet صلى الله عليه وسلم said, "The angels continue to cover him with their wings.''
[Al-Bukhari and Muslim].
Commentary: Many of the Companions of the Prophet صلى الله عليه وسلم were treated by the infidels in the battle of Uhud in a beastly manner out of sheer spite and vengeance. But Islam has strictly forbidden its followers from doing any such thing to its enemies. This Hadith mentions the distinction of 'Abdullah which he received by virtue of his martyrdom. He was martyred in the battle of Uhud and his dead body was badly mutilated by the enemies.