The Messenger of Allah ﷺ said, "Allah has pledged Himself to the one who goes out in His path, driven by nothing but striving in the path of Allah, faith in Me, and belief in My messengers, that I guarantee to admit him into Paradise or return him to the home from which he set out, having gained whatever reward or spoils he attained."
حدثنا عفان حدثنا عبد الواحد يعني ابن زياد قال حدثنا عمارة بن القعقاع حدثنا أبو زرعة واسمه هرم بن عمرو بن جرير أنه سمع
قال رسول الله ﷺ انتدب الله لمن خرج في سبيله لا يخرجه إلا جهاد في سبيل الله وإيمانا بي وتصديقا برسلي أنه علي ضامن أن أدخله الجنة أو أرجعه إلى مسكنه الذي خرج منه نائلا ما نال من أجر أو غنيمة
Its isnad is sahih. Bukhari related it, 15/1, and Muslim in the Book of Leadership, chapter on the merit of jihad and setting out for the sake of Allah, and in the Book of Faith, 107. The rest related something similar, all of them in the Book of Jihad. The hadith has already appeared at 1757.