“Verbally abusing a Muslim is Fusuq disobedience and fighting him is Kufr (ungratefulness to Allah).’”

قَالَ رَسُولُ اللَّهِ ﷺ سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ