Musnad Abu Ya'la al-Mawsili 42:22

Zuhayr narrated to us, Yahya bin Sa’id narrated to us, from Sa’d bin Ishaq, Zaynab narrated to me, from Abu Sa’id al-Khudri, that a man from the Muslims said: "O Messenger of Allah, what do you see regarding these illnesses that afflict us? What is there for us in them?" He said: "Expiations." He said: "O Messenger of Allah, even if they are little?" He said: "Even if it is a thorn or something greater than it." He said: So he prayed against himself that the fever would not leave him until he died, and that it would not occupy him from Hajj, nor ‘Umrah, nor Jihad in the way of Allah, nor a prescribed prayer in congregation. No person touched his body except that he felt its heat, until he died.