Catechism of the Catholic Church §2861 — excerpt
In the fourth petition, by saying "give us," we express in communion with our brethren our filial trust in our heavenly Father. "Our daily bread" refers to the earthly nourishment necessary to everyone for subsistence, and also to the Bread of Life: the Word of God and the Body of Christ.
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.