Sunan an-Nasa'i, Book 25, Hadith 39 (In-Book) ⓘ
Abu Hurairah said: "I heard the Messenger of Allah say: 'Allah has guaranteed: 'For the one who goes out in the cause of Allah, and nothing makes him do that except faith in Me, and Jihad in My cause - that He will admit him to Paradise whether he is killed or he dies, or He will return him to his home from which he departed with whatever he has earned of reward or spoils of war.'"
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ سَعِيدٍ، عَنْ عَطَاءِ بْنِ مِينَاءَ، مَوْلَى بْنِ أَبِي ذُبَابٍ سَمِعَ أَبَا هُرَيْرَةَ، يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " انْتَدَبَ اللَّهُ عَزَّ وَجَلَّ لِمَنْ يَخْرُجُ فِي سَبِيلِهِ لاَ يُخْرِجُهُ إِلاَّ الإِيمَانُ بِي وَالْجِهَادُ فِي سَبِيلِي أَنَّهُ ضَامِنٌ حَتَّى أُدْخِلَهُ الْجَنَّةَ بِأَيِّهِمَا كَانَ إِمَّا بِقَتْلٍ أَوْ وَفَاةٍ أَوْ أَرُدَّهُ إِلَى مَسْكَنِهِ الَّذِي خَرَجَ مِنْهُ نَالَ مَا نَالَ مِنْ أَجْرٍ أَوْ غَنِيمَةٍ " .
also referenced under: Hadith 3123 (Reference) & Volume 4, Book 25, Hadith 3125 (DarusSalam)