Behold, our Lord shall come with power, to enlighten the eyes of his servants, Alleluia!
It’s the first Antiphon of the first Nocturn of Matins of the Annunciation. The others are: Drop down, ye heavens, from above and let the skies pour down righteousness; let hte earth open and bring forth a Saviour. Behold, the name of the Lord cometh