Salama bin Akwa reported,

On the day of Khaybar, my brother fought fiercely alongside the Messenger of Allah ﷺ. His sword rebounded upon him and killed him. The companions of the Messenger of Allah ﷺ spoke about this and had doubts concerning him, saying he was a man who had died by his own weapon, and so they were uncertain about part of his affair.Salama said, The Messenger of Allah ﷺ returned from Khaybar, and I said, "Messenger of Allah, will you permit me to chant verses before you?"The Messenger of Allah ﷺ gave him permission.Umar said to him, "Be mindful of what you say."Salama said, So I said, "By Allah, had it not been for Allah, we would not have been guided, nor would we have given charity, nor would we have prayed."The Messenger of Allah ﷺ said, "You have spoken the truth.""So send down tranquility upon us and make our feet firm if we meet the enemy, for the polytheists have transgressed against us."When I had finished my chant, the Messenger of Allah ﷺ asked, "Who composed this?"I said, "My brother composed it."The Messenger of Allah ﷺ said, "May Allah have mercy on him."I said, "Messenger of Allah, by Allah, some people are reluctant to pray over him, saying he is a man who died by his own weapon."The Messenger of Allah ﷺ said, "He died striving and as a warrior."Ibn Shihab said, Then I asked the son of Salama bin Akwa, and he narrated to me from his father the same as what Abdul-Rahman had narrated to me, except that the son of Salama said, The Messenger of Allah ﷺ also said, "They are reluctant to pray over him? They have spoken falsely. He died striving and as a warrior, so he has his reward twice over." And the Messenger of Allah ﷺ indicated this with two of his fingers.

قال حدثنا عبد الرزاق قال أخبرنا ابن جريج عن ابن شهاب أخبرني عبد الرحمن بن عبد الله بن كعب بن مالك الأنصاري أن

سلمة بن الأكوع قال

لما كان يوم خيبر قاتل أخي قتالا شديدا مع رسول الله ﷺ فارتد عليه سيفه فقتله فقال أصحاب رسول الله ﷺ في ذلك وشكوا فيه رجل مات بسلاحه شكوا في بعض أمره قال سلمة فقفل رسول الله ﷺ من خيبر فقلت يا رسول الله أتأذن لي أن أرجز بك فأذن له رسول الله ﷺ فقال له عمر اعلم ما تقول قال فقلت والله لولا الله ما اهتدينا ولا تصدقنا ولا صلينا فقال رسول الله ﷺ صدقت فأنزلن سكينة علينا وثبت الأقدام إن لاقينا والمشركون قد بغوا علينا فلما قضيت رجزي قال رسول الله ﷺ من قال هذا قلت أخي قالها فقال رسول الله ﷺ يرحمه الله فقلت يا رسول الله والله إن ناسا ليهابون أن يصلوا عليه ويقولون رجل مات بسلاحه فقال رسول الله ﷺ مات جاهدا مجاهدا قال ابن شهاب ثم سألت ابن سلمة بن الأكوع فحدثني عن أبيه مثل الذي حدثني عنه عبد الرحمن غير أن ابن سلمة قال قال مع ذلك رسول الله ﷺ يهابون الصلاة عليه كذبوا مات جاهدا مجاهدا فله أجره مرتين وقال رسول الله ﷺ بإصبعيه