Thou shalt not be afraid for the terror by night.@Psalm 91:5

Attributed to Ambrose of Milan (340–397) (Te lucis ante terminum); translated from Latin to English in Hymns Ancient and Modern.

Te Lucis Sarum melody (🔊 pdf nwc).

Ambrose of Milan (340–397)

Before the ending of the day,
Creator of the world, we pray
That Thou with wonted love wouldst keep
Thy watch around us while we sleep.

O let no evil dreams be near,
Nor phantoms of the night appear;
Our ghostly enemy restrain,
Lest aught of sin our bodies stain.

Almighty Father, hear our cry
Through Jesus Christ our Lord most high,
Who with the Holy Ghost and Thee
Doth live and reign eternally.