(202) بَابُ سِبَابِ الْمُسْلِمِ فُسُوقٌ
'Abdullah reported that the Prophet, may Allah bless him and granthim peace, said, "Reviling a Muslim is deviant behaviour and killing himis disbelief." (ES)
Reference (ES): Al-Adab Al-Mufrad 431 (ES)
In-book reference (ES): Book 24, Hadith 13 (ES)
English translation (ES): Book 24, Hadith 431 (ES)