The Messenger of Allah ﷺ visited Umm Saaib, or Umm Musayyab, and asked, "What is the matter with you, Umm Saaib," or "Umm Musayyab, that you are shivering?"She replied, "It is the fever, may Allah not bless it."He said, "Do not curse the fever, for it removes the sins of the children of Adam just as the bellows removes impurities from iron."
أن رسول الله ﷺ دخل على أم السائب، أو أم المسيب فقال: ما لك يا أم السائب، أو يا أم المسيب تزفزفين؟ قالت: الحمى لا بارك الله فيها. فقال: لا تسبي الحمى، فإنها تذهب خطايا بني آدم كما يذهب الكير خبث الحديد.
Muslim narrated it in the Book of Righteousness and Kinship (2575), from Ubaydullah bin Umar Qawariri, he said, Yazid bin Zuray told us, he said, Hajjaj Sawwaf told us, he said, Abu Zubayr told me, he said, Jabir bin Abdullah told us, and he related it.Hakim also narrated it (1/346) through another route, from Abu Zubayr, from Jabir bin Abdullah, that the Messenger of Allah ﷺ visited a woman from the Ansar who was sick, and said to her, "Is this the mother of fever?" She said, "Yes." And she cursed it, calling on Allah to curse it. So the Messenger of Allah ﷺ said, "Do not curse it, for it washes away the sins of the servant just as the furnace removes the impurity from iron."He said, "This is a hadith that is sahih according to the criterion of Muslim, though the two of them did not narrate it with this wording. Muslim only narrated it with different wording, from the hadith of Hajjaj bin Abu Uthman, from Abu Zubayr."I say, it is as he said, and Hajjaj bin Abu Uthman is the same as Hajjaj Sawwaf, as mentioned previously.