The Prophet ﷺ said, "The first thing we begin with on this day of ours is that we pray, then we return and sacrifice. Whoever does this has followed our Sunnah." The hadith continues. In another narration, "and has followed the Sunnah of the Muslims."
قال النبي ﷺ: إن أول ما نبدأ به في يومنا هذا نصلي، ثم نرجع فننحر، من فعله فقد أصاب سنتنا الحديث. وفي رواية: وأصاب سنة المسلمين
Bukhari narrated it in the Book of Sacrifices (5545), and Muslim in the Book of Sacrifices (7:1961), both through the route of Muhammad bin Bashshar, with Muslim adding Muhammad bin Muthanna, who said, Muhammad bin Jafar (Ghundar) narrated to us, Shubah narrated to us, from Zubayd Ayami, from Shaybi, from Bara bin Azib, and he mentioned it.The second narration is from Bukhari (5556) and Muslim (4:1961), both through the route of Khalid bin Abdullah, from Mutarrif, from Amir Shaybi, with the same wording.