O ADONAI

O Lord and Ruler of the house of Israel, Who appearedst unto Moses in a flame of fire in the bush, and gavest unto him the Law in Sinai: Come and redeem us with an outstretched arm.

O Lord Jesu Christ, Who as the Angel of the Lord
didst rule and guard God's people of old; 
Who didst appear to Moses in the burning bush,
that told of Thy presence hallowing but not consuming,
and of Thy people's preservation through fiery trials;
Who didst give the Law in Sinai
in cloud and majesty and awe;
Thou didst come to visit mankind oppressed
and didst redeem us therefrom
by the victory of Thy Passion:
Come, we pray Thee, now by Thy grace,
and with Thine outstretched arm deliver us
from the bondage of evil habits
from the crafts and assaults of Satan,
from the tyrany of the world,
and the disorder into which our nature has fallen
Write in our hearts by Thy Spirit
the law in obedience to which we shall find our true freedom,
Thy law of truth and purity and love.

Acts 7:30, 28; Hebrews 12:18-21, 10:16. 

Read more about the Advent “O Antiphons,” which are to be chanted before and after the Magnificat at Vespers for the final seven days of Advent.