The Great O Antiphons, used to bookend the Magnificat in Vespers in the last seven days before Christmas. The Treasury of Daily Prayer includes them in the daily propers section. As each of these Old Testament names for God is prayed, and Christ is invoked to come to us, the clarity of whom the Blessed Mother bore is driven home in an unmistakable way, climaxing in the confession that He is Emmanuel, God with us. The hymn of the day for the fourth Sunday in Advent is the versification of these antiphons “O Come, O Come, Emmanuel.”
O Emmanuel, our king and our Lord, the anointed for the nations and their Savior: Come and save us, O Lord our God.
Chapter: Isaiah 33:22
For the Lord is our judge, the Lord is our lawgiver, the Lord is our king: he will save us.
The Prayer – Christ Almighty, Onlybegotten Son of God, of Thy mercy come Thou to save the people that believeth in Thee; that by Thy wonted kindliness, Thou mayest command us to be freed of very doubt, and fear of our times. Who with the Father.