It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that fever was mentioned in the presence of the Noble Prophet (peace and blessings be upon him), and a person spoke ill of it. The Prophet (peace and blessings be upon him) said to him: Do not speak ill of fever, for surely it cleanses sins just as fire removes the impurities of iron.

It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: If any Muslim man or Muslim woman continues to suffer from any affliction, Allah Almighty causes his (or her) sins (mistakes) to fall away.

It is narrated from Hazrat Ata bin Yasar that the Noble Prophet (peace and blessings be upon him) said: When a believing servant falls ill, Allah Almighty commands the noble scribes (angels): Write for My servant the same (good deeds) that he used to do when he was healthy, until I either call him to Myself or grant him relief from that affliction.

Hazrat Saeed bin Muhab narrates that I went with Hazrat Salman to visit his friend who was ill in Kinda. He said: When Allah afflicts a Muslim with some hardship and then removes it, it becomes an expiation for his sins, and he is pleased with whatever remains. And when Allah afflicts a sinner and a wicked person with some hardship and then grants him well-being, he becomes like that camel whose owner ties its thigh and foreleg so that it cannot walk; it does not know why it was tied, and when it is released, it does not know why it was released.

It is narrated from Hazrat Salman that when any (believing) servant falls ill, an angel submits, "O Lord! Your such-and-such servant is afflicted with illness." Allah Almighty says: "As long as he remains in My covenant, keep recording for him the like of those deeds which he used to do (when he was healthy)."

It is narrated from Hazrat Mu'adh that when Allah Almighty tests His servant with illness, He says to the angel on the left shoulder, "Lift your pen and stop writing," and He commands the angel on the right shoulder, "Write down for My servant the deeds which he used to do (when he was healthy)."

Hazrat Aisha (may Allah be pleased with her) narrates that I heard the Messenger of Allah (peace and blessings be upon him) say: There is no believer who is pricked by a thorn or anything greater than that, except that Allah Almighty raises his rank by one degree in return and forgives his sin (mistake).

Hazrat Abu Huraira (may Allah be pleased with him) says that I do not prefer any discomfort more than fever, (because) indeed it enters every joint of the son of Adam, and Allah Almighty grants a share of reward to each of his joints.

It is narrated from Hazrat Salim that one day Hazrat Abu Darda saw a man and was amazed at his health and strength. He asked him, "Have you ever had a fever? Have you ever suffered any pain (such as a headache, etc.)?" He replied, "No." Hazrat Abu Darda said, "It is bad for him; he will die with his sins."

It is narrated from Hazrat Rabee’ bin Ameelah that there was a Bedouin with Hazrat Ammar. In his presence, people mentioned hardship and illness. Hazrat Ammar said: Have you ever suffered from illness? He replied: No. Hazrat Ammar said: Then you are not one of us. There is no believer who is afflicted with hardship except that his sins fall away like the leaves of a tree. And indeed, when a disbeliever is afflicted with hardship, his example is like that of a camel: when it is tied, it does not know why it has been tied, and when it is released, it does not know why it has been released.