From Sahih Muslim (Hadith 6559):
Abdullah reported:I visited Allah's Messenger (ﷺ) as he was running a high temperature. I touched his body with my hand and said to him: Allah's Messenger, you are running a high temperature, whereupon Allah's Messenger (ﷺ) said: Yes, it is so. I comparatively have a more severe fever than any one of you. 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: When a Muslim falls ill, his compensation is that his minor sins are obliterated just as leaves fall (in autumn). In the hadith transmitted on the authority of Zubair there is (no mention of these words):" I touched his body with my hands
Reference: Muslim 6559