Sahih al-Bukhari 5003
صحيح البخاري#5003SahihNarrated Qatada:I asked Anas bin Malik: "Who collected the Qur'an at the time of the Prophet (ﷺ) ?" He replied, "Four, all of whom were from the Ansar: Ubai bin Ka`b, Mu`adh bin Jabal, Zaid bin Thabit and Abu Zaid
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: 66:25