PREMEDITATED MURDER H 10 "When two Muslims (submitters to Allah) oppose each other with swords, both the killer and the murdered will be in Hell. I (Abu Bakrah) said: 'O Messenger of Allah, praise and peace be upon him, surely, it is only the killer. What about the one who has been killed?' He answered: 'The other was also eager to kill his companion.'" R Bukhari and Muslim with a chain up to (Abu Bakrah) Nafi' son of al-Harith ath-Thaqfi, related, the Messenger of Allah, praise and peace be upon him, said this.
9- وعن أبي بَكرَةَ نُفيع بنِ الحارثِ الثقفيِّ رضي الله عنه : أَنَّ النَّبيَّ صلى الله عليه وآله وسلم ، قَالَ : "إِذَا التَقَى المُسلِمَان بسَيْفَيهِمَا فالقَاتِلُ وَالمَقْتُولُ في النّارِ" قُلتُ : يا رَسُولَ اللهِ ، هذا القَاتِلُ فَمَا بَالُ المقْتُولِ ؟ قَالَ : "إنَّهُ كَانَ حَريصاً عَلَى قتلِ صَاحِبهِ" مُتَّفَقٌ عليهِ .