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