(202) بَابُ سِبَابِ الْمُسْلِمِ فُسُوقٌ
Sa'id ibn Malik reported that the Prophet, may Allah bless himand grant him peace, said, "Reviling a Muslim is deviant behaviour." (ID)
Reference (ID): Al-Adab Al-Mufrad 429 (ID)
In-book reference (ID): Book 24, Hadith 11 (ID)
English translation (ID): Book 24, Hadith 429 (ID)