On it being disliked to curse fever

Riyad as-Salihin (The Meadows of the Righteous)

by Imam Nawawi

322. Chapter: On it being disliked to curse fever

1726. Jabir reported that the Messenger of Allah, may Allah bless him and grant him peace, visited Umm as-Sa'ib or Umm al-Musayyab and said, "What is wrong with you, Umm as-Sa'ib - or Umm al-Musayyab? Why are you shaking?' She said, "The fever, may Allah not bless it.' He said, "Do not curse the fever. It removes the errors of the son of Adam as bellows remove the dross of iron." [Muslim]