Chapter: The severity of disease

I never saw anybody suffering so much from sickness as Allah's Messenger (ﷺ).

I visited the Prophet (ﷺ) during his ailments and he was suffering from a high fever. I said, "You have a high fever. Is it because you will have a double reward for it?" He said, "Yes, for no Muslim is afflicted with any harm but that Allah will remove his sins as the leaves of a tree fall down."