Sahih Muslim 1876a

Zuhayr ibn Harb narrated to me; Jarir narrated to us, from Umarah, namely Ibn al-Qaqqaa, from Abu Zurah, from Abu Hurayrah, who said: The Messenger of Allah, peace and blessings be upon him, said: “Allah has guaranteed care for whoever sets out in His path, with no motive for going out except striving in My path, faith in Me, and affirmation of My messengers. He is under My guarantee that I will admit him to Paradise or return him to his home from which he departed, having received whatever reward or spoils he gained. By the One in whose hand is the soul of Muhammad, no wound received in the path of Allah will come on the Day of Resurrection except that it will be as it was when inflicted: its color the color of blood, and its scent the scent of musk. By the One in whose hand is the soul of Muhammad, were it not difficult for the Muslims, I would never stay behind a detachment fighting in the path of Allah. But I have no means to provide mounts for them, and they have no means of their own, and it is hard for them to stay behind me. By the One in whose hand is the soul of Muhammad, I wish I could fight in the path of Allah, be killed, then fight and be killed, then fight and be killed.”