Sayyiduna Jabir (may Allah be pleased with him) narrates: The fever sought permission to come before the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) asked: "Who are you?" It said: "Umm Mildam." The Prophet (peace and blessings be upon him) ordered it to go to the people of Quba'. Those people then suffered from the fever what Allah Almighty knew. Then they came to the Prophet (peace and blessings be upon him) and complained to him about the fever. The Prophet (peace and blessings be upon him) said: "What do you wish? If you wish, I will pray to Allah Almighty and He will remove it from you; and if you wish, it will become a means of purification for you (that is, of being cleansed of sins)." The people said: "O Messenger of Allah! Will you really do that?" The Prophet (peace and blessings be upon him) said: "Yes." They said: "Then leave it (so that it becomes an expiation for our sins)."
Ahmad and Abu Ya'la recorded it. The narrators of Ahmad are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجنائز / 3822