He reported God’s Messenger as saying, “God may forgive every sin, except in the case of one who dies a polytheist, or one who purposely kills a believer.”
Abu Dawud transmitted it, and Nasa’i transmitted it on the authority of Mu'awiya.
Abu ad-Darda’ reported God’s Messenger as saying, “A believer will continue to go on quickly and well* so long as he does not kill anyone unlawfully, but when he does so he will grow weary.”
Abu Dawud transmitted it.
*i.e. quick to obey God’s commands and observing well what is due to God and man.
Ibn ‘Abbas reported God’s Messenger as saying, “The prescribed punishments are not to be inflicted in mosques and a father is not to be killed for a son.”
Narrated Abu Umama b. Sahl b. Hunaif told that when ‘Uthman b. ‘Affan was besieged he looked down and said:
I adjure you by God. Are you aware that God’s Messenger said, “It is not lawful to kill a man who is a Muslim except for one of three reasons: fornication after marriage, or unbelief after accepting Islam, or wrongfully killing someone, for which he may be killed”? I swear by God that I have not committed fornication before or after the coming of Islam, or apostatised since I swore allegiance to God's Messenger, or killed anyone whom God has declared inviolate; so for what reason do you want to kill me?
Tirmidhi, Nasa'i and Ibn Majah transmitted it, and Darimi gives the wording of the tradition.
