Sahih Bukhari Volume 9, Book 97, Hadith 7465

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ تَكَفَّلَ اللَّهُ لِمَنْ جَاهَدَ فِي سَبِيلِهِ، لاَ يُخْرِجُهُ مِنْ بَيْتِهِ إِلاَّ الْجِهَادُ فِي سَبِيلِهِ، وَتَصْدِيقُ كَلِمَتِهِ أَنْ يُدْخِلَهُ الْجَنَّةَ، أَوْ يَرُدَّهُ إِلَى مَسْكَنِهِ بِمَا نَالَ مِنْ أَجْرٍ أَوْ غَنِيمَةٍ ‏"

Narrated By Abu Huraira : Allah's Apostle said, "Allah guarantees (the person who carries out Jihad in His Cause and nothing compelled him to go out but Jihad in His Cause and the belief in His Word) that He will either admit him into Paradise (Martyrdom) or return him with reward or booty he has earned to his residence from where he went out."