Catechism of the Catholic Church §2837 — excerpt
"Daily" (epiousios) occurs nowhere else in the New Testament. Taken in a temporal sense, this word is a pedagogical repetition of "this day," to confirm us in trust "without reservation."
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: St. Ignatius of Antioch, Ad Eph. 20, 2 PG 5, 661 · St. Augustine, Sermo 57, 7: PL 38, 389 · St. Peter Chrysologus, Sermo 67 PL 52, 392