That the Messenger of Allah ﷺ said: "The deeds of everyone who dies are sealed. Except for the one who dies guarding the frontier from the enemy, in the cause of Allah. For indeed his actions are increased for him until the Day of Judgement, and he is secure from the tribulation of the grave." And I heard the Messenger of Allah ﷺ saying: "The Mujahid is one who strives against his own soul."  

أَنَّ عَمْرَو بْنَ مَالِكٍ الْجَنْبِيَّ أَخْبَرَهُ أَنَّهُ سَمِعَ فَضَالَةَ بْنَ عُبَيْدٍ يُحَدِّثُ عَنْ رَسُولِ اللَّهِ ﷺ أَنَّهُ قَالَ كُلُّ مَيِّتٍ يُخْتَمُ عَلَى عَمَلِهِ إِلاَّ الَّذِي مَاتَ مُرَابِطًا فِي سَبِيلِ اللَّهِ فَإِنَّهُ يُنْمَى لَهُ عَمَلُهُ إِلَى يَوْمِ الْقِيَامَةِ وَيَأْمَنُ مِنْ فِتْنَةِ الْقَبْرِ وَسَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ الْمُجَاهِدُ مَنْ جَاهَدَ نَفْسَهُ