It is narrated from Majza'ah bin Zahir (may Allah have mercy on him) that Sayyiduna Amir bin al-Akwa' (may Allah be pleased with him) fought an enemy soldier in single combat (on the battlefield) and killed him, but in the process he himself was also wounded (by his own sword turning back on him). The narrator relates that when this incident was mentioned before the Prophet (peace and blessings be upon him), he (peace and blessings be upon him) said: "For him there is a double reward."
Takhrij: This narration is found with the detailed story in Sahih al-Bukhari (4196) and Sahih Muslim (1802), in which it is stated explicitly that Amir bin al-Akwa' (may Allah be pleased with him) was accidentally wounded by his own sword and attained martyrdom, upon which the Prophet (peace and blessings be upon him) gave him the glad tidings of a double reward.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 4028
Hadith Gradingمحدثین:إسناده ضعيف، مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده ضعيف مرسل » «انفرد به المصنف من هذا الطريق»
It is narrated from Iyas bin Salamah bin al-Akwa' (may Allah have mercy on him) that his paternal uncle (Amir bin al-Akwa' (may Allah be pleased with him)) was wounded on the day of Khaybar and killed a (enemy) man, so the Messenger of Allah (peace and blessings be upon him) said (honouring him): "For you there is a double reward."
The chain of this hadith is sahih (authentic), and its supporting reports are in Sahih al-Bukhari and Sahih Muslim, where the bravery and martyrdom of Amir bin al-Akwa' (may Allah be pleased with him) are mentioned in detail.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 4029
Hadith Gradingمحدثین:إسناده ضعيف، مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده ضعيف مرسل » «أخرجه صحيح البخاري برقم: 3960، وأخرجه صحيح مسلم برقم: 1802، وأخرجه المعجم الكبير للطبراني برقم: 6230، 6274، وأخرجه المعجم الأوسط للطبراني برقم: 2172، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 4275»