A liturgical comment for the eighteenth Sunday after Pentecost.
This Sunday was in former times left vacant, for since the liturgy of Ember Saturday continued into Sunday morning, today had no Mass text of its own. When later on the custom of waiting until the evening to celebrate the Holy Sacrifice on Ember Saturday had ceased, the Mass composed in the sixth century for the Dedication of the Church of St. Michael at Rome was borrowed for the eighteenth Sunday after Pentecost.
Consequently all the Propers of this Mass refer to the consecration of a church. "I rejoiced at the things that were said to me: We shall go into the house of the Lord" (Introit and Gradual). "Moses consecrated an altar to the Lord" (Offertory). "Bring up sacrifices and come into his courts: adore ye the Lord in His holy court" (Communion).
We have here a symbol of heaven whither all nations shall flow at the end of time. The Epistle speaks of those who await the revelation of our Lord at His second coming. They will rejoice forever in the Lord's presence in the peace which, according to the prophets, He will give to those who await Him (Introit, Gradual); a peace assured to us by our Lord through His death on the cross.
Already in the Church all enjoy this pardon and peace, thanks to the power which our Lord has entrusted to His priests, and indeed in this Mass, coming after Ember Saturday, allusion is made to the Priesthood. Like our divine Redeemer, who went about exercising His ministry, curing the soul of the paralytic at the same time that he healed his body—“My son, thy sins are forgiven thee”--those who have just been ordained preach the Word of Christ (Epistle), celebrate the Holy Sacrifice (Offertory), and remit sins (Gospel). Thus they prepare men to receive their divine Judge.
Source: Dom Gaspar Lefebvre, OSB, 1945, adapted and abridged.