Luke 11:3

Verse 3. In the Greek it is called επιουσιον; that is supersubstantial. This is not the bread that goeth into the body, but the bread of eternal life, that supports the life of the soul. It is here called daily bread. Receive then daily, what will daily profit you; and continue so to live, that you may be daily in proper dispositions for receiving it. All who are under sin, have received a wound, and must seek for a cure. The cure is this heavenly and most venerable sacrament. Saint Augustine, Serm. ii. de verbo Dei.