(4) باب سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ
It was narrated from Abu Hurairah that the Prophet (ﷺ) said:
"Verbally abusing a Muslim is Fusuq (disobedience) and fighting himisKufr (ungratefulness to Allah)." (TR)
Reference (TR): Sunan Ibn Majah 3940 (TR)
In-book reference (TR): Book 36, Hadith 15 (TR)
English translation (TR): Vol. 5, Book 36, Hadith 3940 (TR)