كتاب الكلام
56  
Speech

Malik related to me from Abdullah ibn Dinar from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "If a man says to his muslim brother, 'O kafir!' it is true about one of them."

حَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ قَالَ لأَخِيهِ يَا كَافِرُ ‏.‏ فَقَدْ بَاءَ بِهَا أَحَدُهُمَا ‏"‏ ‏.‏
Sunnah.com reference : Book 56, Hadith 1
USC-MSA web (English) reference : Book 56, Hadith 1
Arabic reference : Book 56, Hadith 1814