Sahih Muslim
The Book of Tribulations and Portents of the Last Hour — Hadith #7074
Scholarly Consensus: Sahih How we grade
وَحَدَّثَنَاهُ أَحْمَدُ بْنُ عَبْدَةَ الضَّبِّيُّ، حَدَّثَنَا حَمَّادٌ، عَنْ أَيُّوبَ، وَيُونُسَ، وَالْمُعَلَّى بْنِ زِيَادٍ،
عَنِ الْحَسَنِ، عَنِ الأَحْنَفِ بْنِ قَيْسٍ، عَنْ أَبِي بَكْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم
" إِذَا الْتَقَى الْمُسْلِمَانِ بِسَيْفَيْهِمَا فَالْقَاتِلُ وَالْمَقْتُولُ فِي النَّارِ " .
When two Muslims confront each other with their swords, both the slayer and the slain are doomed to Hell-Fire.
Chain of Narration (Isnad)
Hadith Grading
Each grade below reflects one scholar's assessment of the chain of transmission. The grade describes the chain, not the Prophet's words. How we grade
Scholarly Consensus: Sahih