(27) باب قِتَالِ الْمُسْلِمِ
It was narrated that 'Abdullah said:
"Fighting a believer is Kufr and defaming him is evildoing." (ID)
Reference (ID): Sunan an-Nasa'i 4113 (ID)
In-book reference (ID): Book 37, Hadith 148 (ID)
English translation (ID): Vol. 5, Book 37, Hadith 4118 (ID)