Reference : Hisn al-Muslim 246
بِسْمِ اللَّهِ 
وَاللَّهُ أَكْبَرُ 
[اللَّهُمَّ مِنْكَ وَلَكَ] 
اللَّهُمَّ تَقَبَّلْ مِنِّي
Bismillāh wallāhu Akbar 
[Allāhumma minka wa lak] 
Allāhumma taqabbal minnī.


With the Name of Allah,
Allah is the Most Great! 
[O Allah, from You and to You.] 
O Allah, accept it from me.

Reference:
Muslim 3/ 1557, Al-Bayhaqi 9/287.

Chapter: When slaughtering or offering a sacrifice