al-Walid bin Jmyl الوليد بن جميل · The Book on Virtues of Jihad

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." There are narrations on this topic…