This hymn is used for Lauds on Sundays and weekdays during the Season of Advent in both Forms.
Hark! an awful voice is sounding;
“Christ is nigh!” it seems to say;
“Cast away the dreams of darkness,
O ye children of the day!”
Startled at the solemn warning,
Let the earth-bound soul arise;
Christ her Sun, all sloth dispelling,
Shines upon the morning skies.
Lo! the Lamb so long expected,
Comes with pardon down from Heav’n;
Let us haste, with tears of sorrow,
One and all to be forgiven.
So, when next He comes with glory,
Wrapping all the earth in fear,
May He then as our Defender
On the clouds of Heav’n appear.
Honour, glory, virtue, merit,
To the Father and the Son,
With the everlasting Spirit,
While eternal ages run.
The original Latin text is found here.