Meaning & value
In it he roots the liturgy of the Church back in the story of the Exodus. Moses demanded that Pharoah let the people go. Why? In order that they could sacrifice, as God had commanded them. So the Exodus happened; but liberated Israel only became a people, the holy people of God, once God himself at Mount Sinai had given them his law, which in great part was a law of worship. Later on, in the time of the monarchy, the worship of the desert was formalised in the Temple in Jerusalem. That all centred on the rite of sacrifice, but it also included psalms and prayers.For those unable to participate directly in the Temple worship, the worship of the synagogue was instituted as an extension, or legitimate substitute. There, in every synagogue, the Torah, God's holy law, was enthroned and brought out as a sign of his presence; and there the people met to praise God, even without sacrifice, in a set structure of prayers, readings, psalms, intercessions, hymns, blessings.
All of that of course we understand as an anticipation or foreshadowing of the new dispensation made in Christ. Animal sacrifices in the Temple ceased, once Christ had offered once for all his perfect and all-sufficient sacrifice on the Cross. The shadow now gave place to reality, as the book of Hebrews constantly insists.
Does the perfect worship offered by Jesus then replace our prayer? Certainly not! On the contrary: it enables it. So St. Paul cried out: I beseech you brethren, by the mercy of God, that you offer your bodies as a living sacrifice, holy and acceptable to God, which is your rational service (Rm 12:1).
We who belong to Christ are now constituted as the new Israel. Like Israel of old, we are defined as a people who have been redeemed, set free from slavery, only at the most radical level - as St. Paul puts it, we are freed from the slavery to sin. And why? In order that we might offer true and acceptable worship to God. As Jesus said to the Samaritan woman: the kind of worshipper the Father seeks is one who will worship in spirit and in truth (Jn 4:23)
The central act of the Church's worship is the Holy Eucharist; the Eucharistic sacrifice. This is Christ's own offering, Christ's own action: one with Calvary; one with the eternal intercession offered by him in heaven. Here the Church is most fully herself, here she most fully acts. Yet even if the liturgy is very solemn and elaborate, it's all rather quickly accomplished. In its essence it takes only minutes, or even seconds. There's a healthy Christian instinct that wants somehow to prolong this moment, to savour it, to respond to it in praise and thanksgiving, in order to live it. So there is the Divine Office. We can think of it as set all around the Mass, pointing to it, flowing from it, leading back to it: much as the liturgy of the synagogue pointed to the liturgy of the ancient Temple.