NASAI-KUBRA 3570:
from Abū Mūsá —
The Prophet [SAW] said: "If two Muslims confront each other with swords, and one kills the other, they will both be in Hell." It was 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." (Using translation from Nasāʾī 4118)
الكبرى للنسائي ٣٥٧٠:
عن ابو موسى —
عَنِ النَّبِيِّ ﷺ قَالَ «إِذَا تَوَاجَهَ الْمُسْلِمَانِ بِسَيْفَيْهِمَا فَقَتَلَ أَحَدُهُمَا صَاحِبَهُ فَهُمَا فِي النَّارِ» قِيلَ يَا رَسُولَ اللهِ هَذَا الْقَاتِلُ فَمَا بَالُ الْمَقْتُولِ؟ قَالَ «أَرَادَ قَتْلَ صَاحِبِهِ»
hadithunlocked.com