December 18 - O Adonai
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.
O Lord and Ruler 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.
With outstretched arms - for how else would He redeem us, but by stretching out His arms on the Cross? This is the same God of the Old Testament, the "I Am" who spoke to Moses from the bush that burned but did not turn to ash - the God Who would be crucified but return from the dead. The Jews never spoke the sacred name of God, but frequently called Him Adonai, Lord. Emmanuel Who is coming to redeem us as a small child with arms outstretched to hold the whole world in love from His manger - this is Adonai. It is hard to see the ruler of Israel and the King of the World in this fragile infant, yet this is Adonai!
Fr. Z's commentary here and here.
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.