Sunan an-Nasa'i #4124 · The Book of Fighting [The Prohibition of Bloodshed]

Sunan an-Nasa'iIt was narrated from Abu Musa Al-Ash'ari that
Sunan an-Nasa'i · Book 37 · The Book of Fighting [The Prohibition of Bloodshed]
Sunan an-Nasa'i · كتاب 37 · كتاب القتال [تحريم سفك الدماء]
The Messenger of Allah [SAW] said: "If two Muslims confront each other with swords and one of them kills the other, then the killer and the slain will both be in Hell." A man said: "O Messenger of Allah, (we understand about) the killer, but what about the one who is killed?" He said: "He wanted to kill his companion
أَخْبَرَنَا مُجَاهِدُ بْنُ مُوسَى، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، - وَهُوَ ابْنُ عُلَيَّةَ - عَنْ يُونُسَ، عَنِ الْحَسَنِ، عَنْ أَبِي مُوسَى الأَشْعَرِيِّ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ إِذَا تَوَاجَهَ الْمُسْلِمَانِ بِسَيْفَيْهِمَا فَقَتَلَ أَحَدُهُمَا صَاحِبَهُ فَالْقَاتِلُ وَالْمَقْتُولُ فِي النَّارِ ‏"‏ ‏.‏ قَالَ رَجُلٌ يَا رَسُولَ اللَّهِ هَذَا الْقَاتِلُ فَمَا بَالُ الْمَقْتُولِ قَالَ ‏"‏ إِنَّهُ أَرَادَ قَتْلَ صَاحِبِهِ ‏"‏ ‏.‏
Reference : Sunan an-Nasa'i 4124In-book reference : Book 37, Hadith 159