Sahih al-Bukhari 4998
صحيح البخاري#4998SahihNarrated Abu-Huraira:Gabriel used to repeat the recitation of the Qur'an with the Prophet (ﷺ) once a year, but he repeated it twice with him in the year he died. The Prophet (ﷺ) used to stay in I`tikaf for ten days every year (in the month of Ramadan), but in the year of his death, he stayed in I`tikaf for twenty 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: 66:20