(1) بَابُ مَا جَاءَ فِي كَفَّارَةِ الْمَرَضِ
Narrated Abu Sa`id Al-Khudri and Abu Huraira:
The Prophet (ﷺ) said, "No fatigue, nor disease, nor sorrow, nor sadness, nor hurt, nor distress befalls a Muslim, even if it were the prick he receives from a thorn, but that Allah expiates some of his sins for that."
Reference: Sahih al-Bukhari 5641, 5642
In-book reference: Book 75, Hadith 2
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 70, Hadith 545