Sunan an-Nasa'i 4112

Arabic

أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا جَرِيرٌ، عَنْ مَنْصُورٍ، عَنْ أَبِي وَائِلٍ، قَالَ قَالَ عَبْدُ اللَّهِ سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ ‏.‏

Translation

It was narrated that Abu Wa'il said:"'Abdullah said: 'Defaming a Muslim is evildoing and fighting him is Kufr

→ Narrated by Abu Wa'il

Authenticity

Sahih · Abu Ghuddah

Reference