"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?"'
Jami` at-Tirmidhi Book 33, Hadith 1