'Abdullah reported: I visited Allah's Messenger (ﷺ) as he was running high temperature. I touched his body with my bard and said to him: Allah's Messenger, you are running high temperature, whereupon Allah's Messenger (ﷺ) said: Yes, it is so. I have as severe a fever as two men among you have. I said: Is it because there is a double reward in store for you? Thereupon Allah's Messenger (ﷺ) said: Yes, it is so. And Allah's Messenger (ﷺ) again said: No Muslim is afflicted with harm because of sickness or anything else but Allah obliterates his sins because of it just as the tree sheds its leaves. In the hadith transmitted on the authority of Zuhair there is (no mention of these words):" I touched his body with my hands."
Hadith Referenceصحيح مسلم / كتاب البر والصلة والآداب / 2571
This hadith has been transmitted on the authority of jarir and the hadith transmitted on the authority of Abu Mu'awiyahh (RA) there is an addition of these words: He said: Yes, by Him in Whose Hand is my life, there is no Muslim upon the earth." The rest of the hadith is the same.
Hadith Referenceصحيح مسلم / كتاب البر والصلة والآداب / 2571