Sahih al-Bukhari 4171
صحيح البخاري#4171Sahihحَدَّثَنَا إِسْحَاقُ، حَدَّثَنَا يَحْيَى بْنُ صَالِحٍ، قَالَ حَدَّثَنَا مُعَاوِيَةُ ـ هُوَ ابْنُ سَلاَّمٍ ـ عَنْ يَحْيَى، عَنْ أَبِي قِلاَبَةَ، أَنَّ ثَابِتَ بْنَ الضَّحَّاكِ، أَخْبَرَهُ أَنَّهُ، بَايَعَ النَّبِيَّ صلى الله عليه وسلم تَحْتَ الشَّجَرَةِ.
Narrated Abu Qilaba:that Thabit bin Ad-Dahhak had informed him that he was one of those who had given the Pledge of allegiance (of Al-Hudaibiya) beneath the Tree
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: 64:213