We beseech Thee, O Lord, let our hearts be graciously enlightened by Thy holy radiance, that we may serve Thee without fear in holiness and righteousness all the days of our life; that so we may escape the darkness of this world, and by Thy guidance attain the land of eternal brightness; through Thy mercy, O blessed Lord, Who dost live and govern all things, world without end–Amen.

Sarum Breviary, A. D. 1085

Almighty and everlasting God, the Brightness of faithful souls, fill the world with Thy glory, we pray Thee, and show Thyself, by the radiance of Thy light, to all the nations of the world, through Jesus Christ, our Lord–Amen.

Gregorian Sacramentary, A. D. 590