صَحِيحُ مُسْلِمٍ
Sahih Muslim 157 i
The Book of Tribulations and Portents of the Last Hour
If Two Muslims Confront One Another With Their Swords
وَحَدَّثَنَا مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، حَدَّثَنَا مَعْمَرٌ، عَنْ هَمَّامِ بْنِ مُنَبِّهٍ، قَالَ هَذَا مَا حَدَّثَنَا أَبُو هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم فَذَكَرَ أَحَادِيثَ مِنْهَا وَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لاَ تَقُومُ السَّاعَةُ حَتَّى تَقْتَتِلَ فِئَتَانِ عَظِيمَتَانِ وَتَكُونُ بَيْنَهُمَا مَقْتَلَةٌ عَظِيمَةٌ وَدَعْوَاهُمَا وَاحِدَةٌ .
Abu Huraira reported Allah's Messenger (ﷺ) many ahadith and one of them was this: The last Hour will not come until the two parties (of Muslims) confront each other and there is a large-scale massacre amongst them and the claim of both of them is the same.
Sahih Muslim, 157 iSahihصحيح