I visited the Prophet (ﷺ) during his illness and touched him while he was having a fever. I said to him,
"You have a high fever; is it because you will get a double reward?" He said, "Yes. No Muslim is
afflicted with any harm, but that his sins will be annulled as the leave of a tree fall down."
Sahih al-Bukhari Book 75, Hadith 21