Sahih al-Bukhari 7399
Sahih al-Bukhari · Book 97: Oneness, Uniqueness of Allah (Tawheed) · Asking Allah with His Names and seeking refuge with them
Narrated Anas:
حَدَّثَنَا حَفْصُ بْنُ عُمَرَ ، حَدَّثَنَا هِشَامٌ ، عَنْ قَتَادَةَ ، عَنْ أَنَسٍ ، قَالَ ضَحَّى النَّبِيُّ صلى الله عليه وسلم بِكَبْشَيْنِ، يُسَمِّي وَيُكَبِّرُ.
The Prophet (ﷺ) slaughtered two rams as sacrifice and mentioned Allah's Name and said, "Allahu-Akbar" while slaughtering).