Sahih al-Bukhari 5662
صحيح البخاري#5662SahihNarrated 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 75:22