Sahih al-Bukhari 543
صحيح البخاري#543SahihNarrated Ibn `Abbas:"The Prophet (ﷺ) prayed eight rak`at for the Zuhr and `Asr, and seven for the Maghrib and `Isha prayers in Medina." Aiyub said, "Perhaps those were rainy nights." Anas said, "May be
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: 9:20