(5) باب ذِكْرِ مَا يَحِلُّ بِهِ دَمُ الْمُسْلِمِ
It was narrated that 'Amr bin Ghalib said:
"Aishah said: 'Do you not know that the Messenger of Allah [SAW] said: It is not permissible to shed the blood of a Muslim, except a man who committed adultery after being married, or one who reverted to Kufr after becoming Muslim, or a life for a life.'"
Reference: Sunan an-Nasa'i 4017
In-book reference: Book 37, Hadith 52
English translation: Vol. 5, Book 37, Hadith 4022