مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 3807
Jihad
(Section III) - Section 1
وَعَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: يَضْحَكُ اللَّهُ تَعَالَى إِلَى رَجُلَيْنِ يَقْتُلُ أَحَدُهُمَا الْآخَرَ يَدْخُلَانِ الْجَنَّةَ: يُقَاتِلُ هَذَا فِي سَبِيلِ اللَّهِ فَيُقْتَلُ ثُمَّ يَتُوبُ اللَّهُ على الْقَاتِل فيستشهد
Abu Huraira reported God's Messenger as saying, "God most high will cheerfully welcome two men one of whom kills the other. They will enter paradise, one having fought in God’s path and been killed, and the slayer, after receiving God's pardon, having died as a martyr."* * The man who had fought and killed a Muslim later became a Muslim himself and was killed in the course of jihad. (Bukhari and Muslim.)
Mishkat al-Masabih, 3807مُتَّفَقٌ عَلَيْهِ (الألباني)