Sahih Bukhari

Narrated Ibn `Abbas:Allah's Messenger (ﷺ) entered upon sick man to pay him a visit, and said to him, ""Don't worry, Allah willing, (your sickness will be) an expiation for your sins."" The man said, ""No, it is but a fever that is boiling within an old man and will send him to his grave."" On that, the Prophet (ﷺ) said, ""Then yes, it is so