Sunan an-Nasa'i #4113 · The Book of Fighting [The Prohibition of Bloodshed]

Sunan an-Nasa'iIt was narrated that 'Abdullah said
Sunan an-Nasa'i · Book 37 · The Book of Fighting [The Prohibition of Bloodshed]
Sunan an-Nasa'i · كتاب 37 · كتاب القتال [تحريم سفك الدماء]
"Fighting a believer is Kufr and defaming him is evildoing
أَخْبَرَنَا مُحَمَّدُ بْنُ الْعَلاَءِ، عَنْ أَبِي مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ شَقِيقٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قِتَالُ الْمُؤْمِنِ كُفْرٌ وَسِبَابُهُ فُسُوقٌ ‏.‏
Reference : Sunan an-Nasa'i 4113In-book reference : Book 37, Hadith 148