Hadith 8897
عَنْ أَبِي بَكْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا تَوَاجَهَ الْمُسْلِمَانِ بِسَيْفَيْهِمَا فَقَتَلَ أَحَدُهُمَا صَاحِبَهُ فَالْقَاتِلُ وَالْمَقْتُولُ فِي النَّارِ قِيلَ هَذَا الْقَاتِلُ فَمَا بَالُ الْمَقْتُولِ قَالَ قَدْ أَرَادَ قَتْلَ صَاحِبِهِ
Narrated from Sayyiduna Abu Bakrah (may Allah be pleased with him), the Messenger of Allah (peace and blessings be upon him) said: When two Muslims confront each other with their swords, and one kills the other, then both the killer and the one killed go to Hell. Someone asked: The killer is understandable, but what is the reason for the slain (going to Hell)? He (peace and blessings be upon him) said: He had intended to kill his companion.