NASAI 4110:
from ʿAbdullāh —
"The Messenger of Allah [SAW] said: 'Defaming a Muslim is evildoing and fighting him is Kufr.'" I said to Abu Wa'il: "Did you hear it from 'Abdullah?" He said: "Yes."
النسائي ٤١١٠:
عن عبد الله —
قَالَ رَسُولُ اللَّهِ ﷺ سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ قُلْتُ لأَبِي وَائِلٍ سَمِعْتَهُ مِنْ عَبْدِ اللَّهِ قَالَ نَعَمْ