Ibn Atik narrates from his father: I heard the Prophet (peace and blessings be upon him) say: "Whoever goes out as a mujahid in the path of Allah" - then he (peace and blessings be upon him) joined three of his fingers together and said - "and where are the mujahidun? Then if he falls from his mount and dies, his reward is due from Allah; or if he dies a natural death, his reward is likewise due from Allah; and whoever is killed outright in battle has earned a good place of return."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1765