Sahih al-Bukhari 4991
صحيح البخاري#4991Sahihحَدَّثَنَا سَعِيدُ بْنُ عُفَيْرٍ، قَالَ حَدَّثَنِي اللَّيْثُ، قَالَ حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، قَالَ حَدَّثَنِي عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ، أَنَّ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ حَدَّثَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " أَقْرَأَنِي جِبْرِيلُ عَلَى حَرْفٍ فَرَاجَعْتُهُ، فَلَمْ أَزَلْ أَسْتَزِيدُهُ وَيَزِيدُنِي حَتَّى انْتَهَى إِلَى سَبْعَةِ أَحْرُفٍ ".
Narrated `Abdullah bin `Abbas:Allah's Messenger (ﷺ) said, "Gabriel recited the Qur'an to me in one way. Then I requested him (to read it in another way), and continued asking him to recite it in other ways, and he recited it in several ways till he ultimately recited it in seven different ways
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 66:13