5 We say in the third petition, “Your will be done as in heaven, so in earth.” What is this? That as the Angels serve You in heaven, so we may serve You in earth. For His holy Angels obey Him; they do not offend Him; they do His commands through the love of Him. This we pray for then, that we too may do the commands of God in love. Again, these words are understood in another way, “Your will be done as in heaven, so in earth.” Heaven in us is the soul, earth in us is the body. What then is, “Your will be done as in heaven, so in earth”? As we hear Your precepts, so may our flesh consent unto us; lest, while flesh and spirit strive together, we be not able to fulfil the commands of God.
6. “Give us this day our daily bread,” comes next in the Prayer. Whether we ask here of the Father support necessary for the body, by “bread” signifying whatever is needful for us; or whether we understand that daily Bread, which you are soon to receive from the Altar; well it is that we pray that He would give it us. For what is it we pray for, but that we may commit no evil, for which we should be separated from that holy Bread. And the word of God which is preached daily is daily bread. For because it is not bread for the body, it is not on that account not bread for the soul. But when this life shall have passed away, we shall neither seek that bread which hunger seeks; nor shall we have to receive the Sacrament of the Altar, because we shall be there with Christ, whose Body we do now receive; nor will those words which we are now speaking, need to be said to you, nor the sacred volume to be read, when we shall see Him who is Himself the Word of God, by whom all things were made, by whom the Angels are fed, by whom the Angels are enlightened, by whom the Angels become wise; not requiring words of circuitous discourse; but drinking in the Only Word, filled with whom they burst forth and never fail in praise. For, “Blessed,” says the Psalm, “are they who dwell in Your house; they will be always praising You.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)