The Prophet ﷺ said, "No thorn or anything greater than that strikes a believer except that it serves as an expiation for him."
حدثنا يحيى عن ابن جريج عن ابن أبي مليكة
عن النبي ﷺ قال ما أصاب المؤمن شوكة فما فوقها تعني إلا كان كفارة له
Its isnad is sahih, mentioned previously at 25305.