Sahih al-Bukhari 4481
صحيح البخاري#4481Sahihحَدَّثَنَا عَمْرُو بْنُ عَلِيٍّ، حَدَّثَنَا يَحْيَى، حَدَّثَنَا سُفْيَانُ، عَنْ حَبِيبٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ عُمَرُ ـ رضى الله عنه ـ أَقْرَؤُنَا أُبَىٌّ، وَأَقْضَانَا عَلِيٌّ، وَإِنَّا لَنَدَعُ مِنْ قَوْلِ أُبَىٍّ، وَذَاكَ أَنَّ أُبَيًّا يَقُولُ لاَ أَدَعُ شَيْئًا سَمِعْتُهُ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم وَقَدْ قَالَ اللَّهُ تَعَالَى {مَا نَنْسَخْ مِنْ آيَةٍ أَوْ نَنْسَأْهَا}
Narrated Ibn `Abbas:`Umar said, "Our best Qur'an reciter is Ubai and our best judge is `Ali; and in spite of this, we leave some of the statements of Ubai because Ubai says, 'I do not leave anything that I have heard from Allah's Messenger (ﷺ) while Allah said: "Whatever verse (Revelations) do We abrogate or cause to be forgotten but We bring a better one or similar to it
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: 65:8