Sahih al-Bukhari 898
صحيح البخاري#898SahihNarrated Abu Huraira through different narrators that the Prophet (ﷺ) said, "It is Allah's right on every Muslim that he should take a bath (at least) once in seven days
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: 11:22