It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) went to the house of Sayyidah Umm al-Sa'ib (may Allah be pleased with her), and she was trembling. The Prophet (peace and blessings of Allah be upon him) asked: "What is the matter with you?" She replied: "I have a fever, may Allah disgrace it." Upon hearing this, the Prophet (peace and blessings of Allah be upon him) said: "Be quiet, do not speak ill of fever, for it removes the sins of a believer just as a furnace removes the impurities of iron."