Paragraph 109. Those who pray the psalms in the name of the Church should be aware of their full sense (sensus plenus), especially their Messianic sense, which was the reason for the Church's introduction of the psalter into its prayer. This Messianic sense was fully revealed in the New Testament and indeed was affirmed publicly by Christ the Lord in person when he said to the apostles: "All that is written about me in the law of Moses and the prophets and the psalms must be fulfilled" (Lk 24:44). The best-known example of this Messianic sense is the dialogue in Matthew's Gospel on the Messiah as Son of David and David's Lord, where Ps 110 is interpreted as Messianic.

Following this line of thought, the Fathers of the Church saw the whole psalter as a prophecy of Christ and the Church and explained it in this sense; for the same reason the psalms have been chosen for use in the liturgy. Though somewhat contrived interpretations were at times proposed, in general the Fathers and the liturgy itself had the right to hear in the singing of the psalms the voice of Christ crying out to the Father or of the Father conversing with the Son; indeed, they also recognized in the psalms the voice of the Church, the apostles, and the martyrs. This method of interpretation also flourished in the Middle Ages; in many manuscripts of the period the Christological meaning of each psalm was set before those praying by means of the caption prefixed. A Christological meaning is by no means confined to the recognized Messianic psalms but is given also to many others. Some of these interpretations are doubtless Christological only in an accommodated sense, but they have the support of the Church's tradition.

On the great feasts especially, the choice of psalms is often based on their Christological meaning and antiphons taken from these psalms are frequently used to throw light on this meaning.