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."
[Abu 'Eisa said:] There are narrations on this topic from 'Uqbah bin 'Amir and Jabir.
The Hadith is Fadalah is a Hasan Sahih Hadith.