Sahih al-Bukhari 1326
صحيح البخاري#1326Sahihحَدَّثَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا يَحْيَى بْنُ أَبِي بُكَيْرٍ، حَدَّثَنَا زَائِدَةُ، حَدَّثَنَا أَبُو إِسْحَاقَ الشَّيْبَانِيُّ، عَنْ عَامِرٍ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ أَتَى رَسُولُ اللَّهِ صلى الله عليه وسلم قَبْرًا، فَقَالُوا هَذَا دُفِنَ، أَوْ دُفِنَتِ الْبَارِحَةَ. قَالَ ابْنُ عَبَّاسٍ ـ رضى الله عنهما ـ فَصَفَّنَا خَلْفَهُ ثُمَّ صَلَّى عَلَيْهَا.
Narrated 'Amir:Ibn `Abbas (who was at that time a boy) said, "Allah's Messenger (ﷺ) came to a grave and the people said, 'He or she was buried yesterday.' " Ibn `Abbas added, "We aligned behind the Prophet (ﷺ) and he led the funeral prayer of the deceased
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: 23:82