The Book on Government
33/36. Chapter:
One who kills a disbeliever then keeps to the right path
Sahih Muslim
حَدَّثَنَا يَحْيَى بْنُ أَيُّوبَ، وَقُتَيْبَةُ، وَعَلِيُّ بْنُ حُجْرٍ، قَالُوا حَدَّثَنَا إِسْمَاعِيلُ، - يَعْنُونَ ابْنَ جَعْفَرٍ - عَنِ الْعَلاَءِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ يَجْتَمِعُ كَافِرٌ وَقَاتِلُهُ فِي النَّارِ أَبَدًا " .
It has been narrated on the authority of Abu Huraira that the Messenger Allah (ﷺ) said: A disbeliever and a believer who killed him will never be gathered together in Hell.
Reference : Sahih Muslim 1891aIn-book reference : Book 33, Hadith 191USC-MSA web (English) reference : Book 20, Hadith 4661