Sunan an-Nasa'i 4048

It was narrated from 'Aishah that:The Messenger of Allah [SAW] said: "It is not permissible to shed the blood of a Muslim except in three cases: An adulterer who had been married, who should be stoned to death; a man who killed another man intentionally, who should be killed; and a man who left Islam and waged war against Allah, the Might and Sublime, and His Messenger, who should be killed, or crucified, or banished from the land