Sahih Muslim
The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wal-Adab)
Book Number: 032 / Hadith Number: 6235
'Abdullah reported: I visited Allah's Messenger (may peace be upon him) 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 (may peace be upon him) 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 (may peace be upon him) said: Yes, it is so. And Allah's Messenger (may peace be upon him) again said: When a Muslim falls ill, his compensation is that his minor sins are obliterated just as leaves tall (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."