It was narrated from Nafi` from Ibn `Umar, that Uthman (رضي الله عنه) looked out at his companions when he was under siege and said:
Why do you want to kill me? I heard the Messenger of Allah (ﷺ) say: `It is not permissible to shed the blood of a Muslim man except in one of three cases; a man who commits zina after being married, so he is to be stoned, or a man who killed deliberately (committed murder), so he is to be killed in retaliation, or a man who apostatised after having become Muslim, so he is to be executed.” By Allah, I never committed zina either during the Jahiliyyah or in Islam, I never killed anyone such that my life should be taken in retaliation; and I never apostatised since [became Muslim bear witness that there is no god but Allah and that Muhammad is His slave and His Messenger,