It is narrated from Hazrat Ibn Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) stood among us and said: "By Him besides whom there is no deity, the blood of a Muslim who testifies that there is no god but Allah and that I am the Messenger of Allah is not lawful, except in one of three cases: if he commits adultery while being married, or if he is killed in retaliation (qisas), or if he abandons his religion and separates from the community."