Abu Hurairah reported,
I heard the Messenger of Allah ﷺ say, "The example of the Mujahid in the path of Allah, and Allah knows best who truly strives in His path, is like that of one who fasts and stands in prayer continuously. Allah has guaranteed for the Mujahid in His path that He will either take his soul and admit him into Paradise, or return him safely with whatever reward or spoils he has gained."
Nasai 3126
Sahihأخبرني عمرو بن عثمان بن سعيد بن كثير بن دينار قال حدثنا أبي عن شعيب عن الزهري قال أخبرني سعيد بن المسيب قال سمعت
أبا هريرة قال
سمعت رسول الله ﷺ يقول مثل المجاهد في سبيل الله والله أعلم بمن يجاهد في سبيل الله كمثل الصائم القائم وتوكل الله للمجاهد في سبيله بأن يتوفاه فيدخله الجنة أو يرجعه سالما بما نال من أجر أو غنيمة
guaranteed for the one who strives in His cause guaranteed for the one who strives in His causeBukhari narrated it in the Book of Jihad, chapter "The Best of People is a Believer Who Strives with His Life and Wealth in the Path of Allah," hadith no. 2787, from the hadith of Shuayb bin Abu Hamza through this same chain, and it is also in Kubra, hadith no. 4332.