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»
The Messenger of Allah (sallallahu alayhi wa sallam) said:, “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.
Mishkat al-Masabih 3647, Book 20, Jihad, Hadith 21. 1 min read