ONE HADITH A DAY
Agreed upon · Authentic
عن ابْنِ عُمَرَ رَضيَ اللهُ عنهُما قَالَ: قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «أَيُّمَا امْرِئٍ قَالَ لِأَخِيهِ: يَا كَافِرُ، فَقَدْ بَاءَ بِهَا أَحَدُهُمَا، إِنْ كَانَ كَمَا قَالَ، وَإِلَّا رَجَعَتْ عَلَيْهِ».
“Ibn ‘Umar (may Allah be pleased with him and his father) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Any person who says to his brother: O disbeliever, it will, indeed, fall upon one of them; if he is as he said, or else it will return to him."”
The Prophet (may Allah's peace and blessings be upon him) warned against a Muslim saying to his Muslim brother: O disbeliever. By saying that word of disbelief, one of them deserves it; if he is as he said, then it applies to the person being addressed, or else the charge of disbelief returns to the sayer.