Narrated ‘Abdallah b. Mas'ud reported God’s Messenger as saying, “The blood of a Muslim who testifies that there is no god but God and that I am God’s Messenger may not lawfully be shed but for one of three reasons:
a life for a life; a married man who commits fornication; and one who turns aside from his religion and abandons the community.”
Ibn ‘Umar reported God’s Messenger as saying, “A believer will continue to find ample scope in his religion as long as he does not kill anyone unlawfully.”
‘Abdallah b. Mas'ud reported God’s Messenger as saying, “Shedding of blood will be the first matter about which judgment will be given on the day of resurrection.”
Al-Miqdad b. al-Aswad told that he said, “Tell me, Messenger of God, supposing I meet an infidel and we fight together and he strikes one of my hands with his sword and cuts it off, then flies for refuge from me to a tree and says he has submitted himself to God (or, in another version, says when I intend to kill him that there is no god but God), shall I kill him after he has said it?” He replied, “Do not kill him.” He protested, “But, Messenger of God, he cut off one of my hands.” God’s Messenger then replied, “Do not kill him, for if you do so, he will be in the position in which you were before you killed him, and you will be in the position in which he was before he made his testimony.”*
(Bukhari and Muslim.)
*i.e. he will now be one for whose killing retaliation may be demanded, and you will be one whose blood may lawfully be shed.
