Sahih al-Bukhari 646
صحيح البخاري#646Sahihحَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا اللَّيْثُ، حَدَّثَنِي ابْنُ الْهَادِ، عَنْ عَبْدِ اللَّهِ بْنِ خَبَّابٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّهُ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " صَلاَةُ الْجَمَاعَةِ تَفْضُلُ صَلاَةَ الْفَذِّ بِخَمْسٍ وَعِشْرِينَ دَرَجَةً ".
Narrated Abu Sa`id Al-Khudri:The Prophet (ﷺ) said, "The prayer in congregation is twenty five times superior to the prayer offered by a person alone
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: 10:43