Latin: O Adonai, et Dux domus Israel, qui Moysi in igne flammae rubi apparuisti, et ei in Sina legem dedisti: veni ad redimendum nos in brachio extento.
English: O Lord and Ruler of the house of Israel, who appeared to Moses in the flame of the burning bush and gave him the law on Sinai: come and redeem us with outstretched arms.
Relevant verse of Veni, Veni Emmanuel:
O come, O come, thou Lord of might, Who to Thy tribes on Sinai’s height
In ancient times didst give the Law, in cloud and majesty, and awe.