The Book of Fighting [The Prohibition of Bloodshed]
Sunan an-Nasa'i · 167 hadiths
#3998Sahih
"Killing a believer is more grievous before Allah than the extinction of the whole world."
#3999Sahih
"Killing a believer is more grievous before Allah than the extinction of the whole world."
#4051Hasan
From the Messenger of Allah : "The Verse about Al-Muharabah was revealed concerning them."
#4061Sahih
"If a slave runs away to the land of Shirk, there is no protection (or immunity) for him."