It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) visited a woman of the Ansar and asked her: "Is it Umm Mildam (fever)?" She said: Yes, may Allah curse it. The Messenger of Allah (peace and blessings be upon him) said: "Do not revile it, for it washes away the sins of the servant just as the furnace removes the impurities of iron." This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs did not record it with these words; Imam Muslim recorded it with different wording through the narration of Hajjaj bin Abi Uthman from Abu al-Zubayr.