It can be tempting to pray the Lord's Prayer mechanically, without noticing the precise words that we pray.
Many of the words have multiple spiritual meanings, especially the word, "daily."
Daily bread
The word is used in the petition "Give us this day our daily bread," and is unique, as the Catechism of the Catholic Church explains.
"Daily" (epiousios) occurs nowhere else in the New Testament.
The Catechism then proceeds to highlight three particular meanings behind the word that is used in the Bible.
1Trust in God
Taken in a temporal sense, this word is a pedagogical repetition of "this day," to confirm us in trust "without reservation."
2What is necessary
Taken in the qualitative sense, it signifies what is necessary for life, and more broadly every good thing sufficient for subsistence.
3Eucharistic Bread
Taken literally (epi-ousios: "super-essential"), it refers directly to the Bread of Life, the Body of Christ, the "medicine of immortality," without which we have no life within us. Finally in this connection, its heavenly meaning is evident: "this day" is the Day of the Lord, the day of the feast of the kingdom, anticipated in the Eucharist that is already the foretaste of the kingdom to come. For this reason it is fitting for the Eucharistic liturgy to be celebrated each day.
St. Augustine comments on this last meaning of the Lord's Prayer:
The Eucharist is our daily bread. The power belonging to this divine food makes it a bond of union. Its effect is then understood as unity, so that, gathered into his Body and made members of him, we may become what we receive. . . . This also is our daily bread: the readings you hear each day in church and the hymns you hear and sing. All these are necessities for our pilgrimage.
St. Peter Chrysologus also adds his own reflection:
The Father in heaven urges us, as children of heaven, to ask for the bread of heaven. [Christ] himself is the bread who, sown in the Virgin, raised up in the flesh, kneaded in the Passion, baked in the oven of the tomb, reserved in churches, brought to altars, furnishes the faithful each day with food from heaven.
It is fascinating how one simple word can have such a depth of meaning.
