IV. “Give Us This Day Our Daily Bread”

From The Catechism of the Catholic Church

2837
“Daily” (epiousios) occurs nowhere else in the New Testament. Taken
in a temporal sense, this word is a pedagogical repetition of “this
day,”¹²⁸ to confirm us in trust “without reservation.”
Taken in the qualitative sense, it signifies what is necessary for life, and
more broadly every good thing sufficient for subsistence.¹²⁹ 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.¹³⁰ 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.