Sunan Abi Dawud 2495
سنن أبي داود#2495Sahihحَدَّثَنَا مُحَمَّدُ بْنُ الصَّبَّاحِ الْبَزَّازُ، حَدَّثَنَا إِسْمَاعِيلُ، - يَعْنِي ابْنَ جَعْفَرٍ - عَنِ الْعَلاَءِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ يَجْتَمِعُ فِي النَّارِ كَافِرٌ وَقَاتِلُهُ أَبَدًا " .
Abu Hurairah reported the Apostle of Allaah(ﷺ) as saying “An infidel and the one who killed him will never be brought together in Hell.”
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (1891)
In-book reference: 15:19