Sunan an-Nasa'i #3166 · The Book of Jihad

Sunan an-Nasa'iIt was narrated from Abu Hurairah that the Messenger of Allah
Sunan an-Nasa'i · Book 25 · The Book of Jihad
Sunan an-Nasa'i · كتاب 25 · كتاب الجهاد
"Allah laughs at two men, one of whom killed the other but they both entered Paradise. The first one fought in the cause of Allah and was killed, then Allah accepted the repentance of the one who killed him, and he fought and was martyred
أَخْبَرَنَا مُحَمَّدُ بْنُ سَلَمَةَ، وَالْحَارِثُ بْنُ مِسْكِينٍ، قِرَاءَةً عَلَيْهِ وَأَنَا أَسْمَعُ، عَنِ ابْنِ الْقَاسِمِ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ يَضْحَكُ اللَّهُ إِلَى رَجُلَيْنِ يَقْتُلُ أَحَدُهُمَا الآخَرَ كِلاَهُمَا يَدْخُلُ الْجَنَّةَ يُقَاتِلُ هَذَا فِي سَبِيلِ اللَّهِ فَيُقْتَلُ ثُمَّ يَتُوبُ اللَّهُ عَلَى الْقَاتِلِ فَيُقَاتِلُ فَيُسْتَشْهَدُ ‏"‏ ‏.‏
Reference : Sunan an-Nasa'i 3166In-book reference : Book 25, Hadith 82