The Prophet ﷺ 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. (Using translation from Abū Dāʾūd 2500)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «كُلُّ مَيِّتٍ يُخْتَمُ عَلَى عَمَلِهِ إِلَّا الْمُرَابِطُ فِي سَبِيلِ اللهِ فَإِنَّهُ يَنْمُو لَهُ عَمَلُهُ يَوْمَ الْقِيَامَةِ وَيُؤَمَّنُ مِنَ فَتَّانِ الْقَبْرِ»