Arabic (Original)
حَدَّثَنَا مُؤَمَّلٌ حَدَّثَنَا سُفْيَانُ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ دِينَارٍ سَمِعْتُ ابْنَ عُمَرَ يَقُولُ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ قَالَ لِأَخِيهِ يَا كَافِرُ فَقَدْ بَاءَ بِهَا أَحَدُهُمَا.
English Translation
Mu'ammal told us, Sufyan told us, Abdullah b. Dinar told us: I heard Ibn Umar say: The Messenger of Allah, peace and blessings be upon him, said: "Whoever says to his brother, 'O disbeliever,' then it applies to one of the two of them."