Sahih al-Bukhari 951
صحيح البخاري#951Sahihحَدَّثَنَا حَجَّاجٌ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ أَخْبَرَنِي زُبَيْدٌ، قَالَ سَمِعْتُ الشَّعْبِيَّ، عَنِ الْبَرَاءِ، قَالَ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَخْطُبُ فَقَالَ " إِنَّ أَوَّلَ مَا نَبْدَأُ مِنْ يَوْمِنَا هَذَا أَنْ نُصَلِّيَ، ثُمَّ نَرْجِعَ فَنَنْحَرَ، فَمَنْ فَعَلَ فَقَدْ أَصَابَ سُنَّتَنَا ".
Narrated Al-Bara':I heard the Prophet (ﷺ) delivering a Khutba saying, "The first thing to be done on this day (first day of `Id ul Adha) is to pray; and after returning from the prayer we slaughter our sacrifices (in the name of Allah) and whoever does so, he acted according to our Sunna (traditions)
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: 13:3