Ubayd Allah ibn Umar al-Qawariri narrated to me, Yazid ibn Zuray' narrated to us, al-Hajjaj al-Sawwaf narrated to us, Abu al-Zubayr narrated to me, Jabir ibn Abd Allah narrated to us, that the Messenger of Allah, peace and blessings be upon him, entered upon Umm al-Sa'ib or Umm al-Musayyab and said, "What is the matter with you, O Umm al-Sa'ib or O Umm al-Musayyab, that you are trembling?" She said, "Fever—may Allah not bless it." He said, "Do not curse fever, for it removes the sins of the children of Adam just as the bellows remove the impurities of iron."