The Song of Songs says aptly: “Who is this who moves forward like the advancing dawn?” Holy Church, inasmuch as she keeps searching for the rewards of eternal life, has been called the dawn. While she turns her back on the darkness of sins, she begins to shine with the light of righteousness.

This reference to the dawn conjures up a still more subtle consideration. The dawn intimates  that the night is over; it does not yet proclaim the full light of day. While it dispels the darkness and welcomes the light, it holds both of them, the one mixed with the other, as it were. Are not all of us who follow the truth in this life daybreak and dawn? While we do some things which already belong to the light, we are not free from the remnants of darkness.

It will be fully day for the Church of the elect when she is no longer darkened by the shadow of sin. What is the place of dawn but the perfect clearness of eternal vision? When dawn has been brought there, it will retain nothing belonging to the darkness of night.

—Gregory the Great, Moral Reflections on Job, 29:2-4