حَدَّثَنَا سَعِيدُ بْنُ مَنْصُورٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، حَدَّثَنِي أَبُو هَانِئٍ، عَنْ عَمْرِو بْنِ مَالِكٍ، عَنْ فَضَالَةَ بْنِ عُبَيْدٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏:‏ ‏"‏ كُلُّ الْمَيِّتِ يُخْتَمُ عَلَى عَمَلِهِ، إِلاَّ الْمُرَابِطَ فَإِنَّهُ يَنْمُو لَهُ عَمَلُهُ إِلَى يَوْمِ الْقِيَامَةِ وَيُؤَمَّنُ مِنْ فَتَّانِ الْقَبْرِ ‏"‏ ‏.‏

Narrated Fadalah ibn Ubayd: The Prophet (PBUH) said: Everyone who dies will have fully complete his action, except one who is on the frontier (in Allah's path), for his deeds will be made to go on increasing till the Day of Resurrection, and he will be safe from the trial in the grave. Translation Not Available

Book reference: Sunan Abi Dawud Book 15 Hadith 2500
Web reference: Sunan Abi Dawud Book 14 Hadith 2494