Abu Umamah bin Sahl bin Hunaif narrated that on the day of siege, 'Uthman bin 'Affan stood overlooking the people, and he said:
I swear to you by Allah! You know that the Messenger of Allah (s.a.w) said: 'The blood of a Muslim man is not lawful, except for one of three (cases):Illegitimate sexual relations after Ihsan (having been married), or apostasy after Islam, or taking a life without right, for which he is killed.' By Allah! I have never committed illegitimate sexual relations, not during Jahiliyyah nor during Islam, and I have not committed apostasy since I gave my pledge to the Messenger of Allah (s.a.w), and I have not taken a life that Allah had made unlawful. So for what do you fight me? '