(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." (TH)
Reference (TH): Sunan Ibn Majah 3941 (TH)
In-book reference (TH): Book 36, Hadith 16 (TH)
English translation (TH): Vol. 5, Book 36, Hadith 3941 (TH)