I heard the Messenger of Allah ﷺ say, "Whoever sustains a wound on his body and gives it as charity, Allah will expiate his sins in proportion to what he gave as charity."
حدثنا عبد الله حدثنا شجاع بن مخلد حدثنا هشيم عن مغيرة عن الشعبي قال قال
سمعت رسول الله ﷺ يقول من جرح في جسده جراحة فتصدق بها كفر الله عز وجل عنه بمثل ما تصدق به
No references are available.
Its isnad is sahih. It was mentioned previously at 22600 in fuller form, and it is one of the additional narrations.