The Prophet (ﷺ) slaughtered two rams as sacrifice and mentioned Allah's Name and said, "Allahu-Akbar" while slaughtering).
Sahih al-Bukhari Book 97, Hadith 28
← Previous Hadith The people said to the Prophet (ﷺ) , "O Allah's Messenger (ﷺ)! Here are people who have recently embraced Islam and they bring meat, and we do not know whether they had mentioned Allah's Name while slaughtering the animals or not." The Prophet (ﷺ) said, "You should mention Allah's Name and eat."

Sahih al-Bukhari Book 97, Hadith 27 Next Hadith → That he witnessed the Prophet (ﷺ) on the Day of Nahr. The Prophet (ﷺ) offered prayer and then delivered a sermon saying, "Whoever slaughtered his sacrifice before offering prayer, should slaughter another animal in place of the first; and whoever has not yet slaughtered any, should slaughter a sacrifice and mention Allah's Name while doing so."

Sahih al-Bukhari Book 97, Hadith 29