بِسْمِ اللَّهِ، وَاللَّهُ أَكْبَرُ
Mentioning Allah's name and takbir at the time of sacrifice
Bismillāhi, wallāhu akbar
In the name of Allah; Allah is the Greatest.
The hadith reports that the Prophet mentioned Allah's name and said takbir when sacrificing.
Sahih al-Bukhari 5565 on sunnah.com