(4) باب سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ
It was narrated from Sa'd that the Messenger of Allah (ﷺ) said:
"Verbally abusing a Muslim is Fusuq (disobedience) and fightinghimis Kufr." (AR)
Reference (AR): Sunan Ibn Majah 3941 (AR)
In-book reference (AR): Book 36, Hadith 16 (AR)
English translation (AR): Vol. 5, Book 36, Hadith 3941 (AR)