Chapter XVII.
David's words indicate that sin is forgiven, when God closes the mouth of the sinner. These same words also apply to Christ, who is the true David, from whom the future gathering of the nations and the foundation of the Church are foreshadowed, ultimately encompassing the sacrifice of Christ and the offering of Martyrs.
O Lord, you will open my lips, and my mouth will proclaim your praise (Psalm 50:17). Whoever praises the Lord will be saved from their enemies, as it is written (Psalm 18:4). And certainly, he had said earlier in the forty-ninth psalm: But to the sinner, God has said: Why do you declare my justices (Psalm 49:17)? Therefore, when he said with his own mouth that God had prohibited the sinner from declaring his justices, certainly by proclaiming the justice of God, he declared that this sin was by no means imputed to him.
And he added: You will open my lips, and my mouth will proclaim your praise. God closes the mouth of the sinner, so that he may not speak the righteousness of God; but he opens the mouth of the righteous, so that he may speak. Therefore, the one whose lips he opens, he absolves from the guilt of sin. But the Lord opens the lips of him who receives the word in the opening of his mouth. Hence, the Apostle asks to be helped by the prayers of the people, that the door of the word may be opened to him to speak the mystery of Christ (Colossians 4:3). But we truly receive language for speech from him who exults in the praises of God. Therefore, it is also valued as such: My tongue is the pen of a swiftly writing scribe (Psalm 45:2), a speech infused to the Prophet.
But if we accept it as being spoken by the person of Christ, let us take care that the scribe is not one who quickly writes the Word of God, which passes through and penetrates the depths of the soul, and inscribes on it either the gifts of nature or of grace; but the tongue to be that holy body derived from the Virgin, which has been purged from the venom of the serpent, and the works of the Gospel have been spread throughout the entire world. It also serves to empty sin, which it has taken upon itself with humility; it has broken its heart, which the Lord has chosen as a sacrifice more than the holocausts for sins which were accustomed to be offered according to the Law. Finally, he says above: 'You did not desire a holocaust and a sin offering; then I said, Behold, I come' (Psalm 29:7-8), that is, I did not consider it robbery to be equal to God, I come taking the form of a servant; I come in the likeness of human acceptance, in the reality of the cross, to prove obedience with the humility of death; that disobedience may be abolished.
Therefore, rightly does he say here: For if you had wanted, I would have given a sacrifice, but you will not be delighted with holocausts. A sacrifice to God is a spirit crushed: a broken and humbled heart, O God, you will not disdain (Psalm 50:18-19). And as I said earlier, it is certain that it agrees with the mystery that the Lord Jesus himself seems to speak here also in his own person, who above expressed it through clear testimony of his person. For He Himself, the true David, strong in hand, true in humility, and gentle, first and last, first in eternity, last in humility: through whose obedience the fault of the human race has been wiped away, and justice has been rejected. He, I say, Jesus, the end and fulfillment of the shadows and the Law, came as the teacher of humility to teach the proud that they must pass from arrogance and the swelling of the heart to gentleness and simplicity. Therefore, how can sin be imputed in the type of His mystery, when in the very mystery there is the forgiveness of sins? Unless perhaps David confessed his own wickedness and the sin he committed, so that he himself might obtain forgiveness of sin and the grace of the mystery.
For what does a man who confesses his sin desire, that he sings from Zion and Jerusalem, saying: Do good, O Lord, in your good will to Zion, so that the walls of Jerusalem may be built (Ibid., 29); unless it is because he is pleased to hasten the gathering of the Church through the call of the Gentiles, which, as a free Jerusalem that is in heaven, would spread the lineage of its faith throughout the whole world and establish the spiritual walls of the doctrine of the apostles by its proclamation?
Therefore, the walls of Jerusalem are fortresses of faith, defenses of debates, and peaks of virtues; the walls of Jerusalem are the gatherings of Churches founded throughout the entire world. For the Church says: 'I am a wall, and my breasts are like towers' (Song of Solomon 8:10). And indeed, the walls of Jerusalem are the assemblies of Churches; for whoever enters the Church with good faith and works becomes a citizen of that heavenly city and a dweller of the city that descends from heaven. This structure builds walls of stones for the living.
Therefore, seeing Jerusalem, the true and Zion, He said: 'When you bless Jerusalem and Zion in your good will, then you will accept the sacrifice of justice' (Psalm 50:21), that is the sacrifice of the body of Christ, who, when speaking of His own passion, said: 'Open to me the gates of justice, and entering through them I will confess to the Lord' (Psalm 117:19). And in the Gospel He said to John: 'Allow it for now; for thus it is fitting for us to fulfill all justice' (Matthew 3:15). And below: Blessed are those who are persecuted for righteousness' sake (Matt. 5:10). Righteousness is Christ. Therefore, he asserts that the sacrifice of Christ will be acceptable to the Father. This is what he also says above: Sacrifice the sacrifice of righteousness, and hope in the Lord (Psalm 4:6). This is the spiritual offering of righteousness, and the burnt offering of fervent devotion, and the infusion of the Holy Spirit, which he says will happen when the souls of the believers begin to approach that spiritual altar of the Lord, renouncing pleasures and delights, and leading them as a plow in their own hearts, so that they may be able to bear the fruits of piety.
Certainly, when you bless the Church acquired from the Gentiles and the spiritual sacrifice of righteousness begins to be celebrated, then the holy martyrs who offered their bodies for Christ are to be commemorated, as if they were offered as sacrificial calves on the sacred altars; just as we find written in the Book of Revelation (Rev. 6:9), 'Under the altar were the souls of those who had offered their bodies for the name of the Lord Jesus by martyrdom, in order to obtain his grace for themselves'; to whom is honor and glory, praise, perpetuity with God the Father and the Holy Spirit from ages past and now and always, and unto all ages of ages. Amen.