Sahih al-Bukhari 1974
صحيح البخاري#1974SahihNarrated `Abdullah bin `Amr bin Al-`As:"Once Allah's Messenger (ﷺ) came to me," and then he narrated the whole narration, i.e. your guest has a right on you, and your wife has a right on you. I then asked about the fasting of David. The Prophet (ﷺ) replied, "Half of the year," (i.e. he used to fast on every alternate day)
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: 30:81