Catholic Commentary
Faithful Proclamation: Witnessing God's Justice Before the Assembly
9I have proclaimed glad news of righteousness in the great assembly. Behold, I will not seal my lips, Yahweh, you know.10I have not hidden your righteousness within my heart. I have declared your faithfulness and your salvation. I have not concealed your loving kindness and your truth from the great assembly.
Psalms 40:9–10 describes the psalmist's public declaration of God's righteousness before the assembled congregation, refusing to conceal divine vindication within himself alone. The passage affirms that experiencing God's saving action compels outward witness and communal proclamation rather than private spiritual possession.
God's righteousness cannot stay locked in your heart—the moment you experience it, you become a herald who must proclaim it.
For the Church as the Body of Christ, these verses constitute a mandate: the righteousness proclaimed by the Head must continue to be proclaimed by the members. The two verses together trace the theological arc from reception of grace to witness — the heartbeat of Christian mission.
Catholic tradition illuminates this passage along three converging lines of teaching.
The Evangelizing Mission of the Church. Evangelii Nuntiandi (Paul VI, 1975, §14) insists that "evangelizing is in fact the grace and vocation proper to the Church, her deepest identity." Psalm 40:9–10 prefigures this ecclesial identity: the psalmist's refusal to conceal divine righteousness is the Old Testament type of which the Church's mission is the antitype. The Catechism of the Catholic Church (§905) echoes this when it teaches that the laity "fulfill their prophetic mission by evangelizing" through both word and the witness of their lives.
The Inseparability of Interior and Public Faith. St. Thomas Aquinas (Summa Theologiae II-II, q. 3, a. 1) teaches that the act of faith is interior assent, but that confession — public acknowledgment — belongs to faith as its necessary fruit. Verse 10's refusal to hide righteousness in the heart mirrors Aquinas's teaching: what is truly held in the heart cannot remain there in isolation. Faith that never moves outward raises questions about whether it was ever truly interior.
Christ as the Perfect Proclaimer. The Christological reading of the Psalms, affirmed by the Second Vatican Council (Dei Verbum §15–16) and taught explicitly by Augustine and Origen, presents Christ as the true speaker of the Psalter. In Hebrews 10:5–7, verses from this very psalm (Ps 40:6–8) are placed on the lips of the incarnate Son. The whole psalm, then, including verses 9–10, is Christ's own confession — making these verses not merely a model for the believer but the very words of the Word.
Contemporary Catholic life is often tempted toward a privatized faith — a "spiritual but not religious" instinct that treats one's relationship with God as a personal lifestyle preference, unsuitable for public conversation. Psalm 40:9–10 challenges this directly and without apology. The psalmist has been delivered (Ps 40:1–3), and that deliverance creates a speaker.
Practically, these verses ask every Catholic: Where is your "great assembly"? It may be your workplace, your family dinner table, your neighborhood, your social media presence. The psalm does not demand professional preaching but it does demand the refusal to hide. A Catholic who has experienced healing in the sacrament of Reconciliation, consolation in prayer, or the grace of a conversion is being asked by this text: have you told someone? The righteousness of God — his fidelity, his mercy, his justice — is not yours to keep.
Additionally, these verses are a call to full, conscious, and active participation in the liturgical assembly. The Mass is the qāhāl gādôl of the New Covenant. To participate authentically — not merely to attend — is itself an act of proclamation, a refusal to hide what God has done.
Commentary
Psalms 40:9 — "I have proclaimed glad news of righteousness in the great assembly"
The Hebrew verb underlying "proclaimed glad news" is biśśartî (from bśr), the same root from which the New Testament Greek euangelizomai — "to evangelize," "to proclaim good news" — derives its semantic force. This is not ordinary speech; it is heralding, announcement, the public declaration of a transformative event. The psalmist does not merely describe God's righteousness (ṣedāqāh) as a legal or abstract attribute but as something that has been experienced and must therefore be shared. The object of proclamation — righteousness — encompasses in Hebrew thought both God's vindicating fidelity to his covenant people and the moral order that flows from that fidelity. To proclaim God's righteousness is to announce that he has acted justly on behalf of the lowly, consistent with his promises.
The setting is the qāhāl gādôl, the "great assembly" — almost certainly the liturgical congregation of Israel gathered for Temple worship. This is a public, communal, and sacred space. The psalmist's proclamation is not a private journal entry or an interior act of devotion alone; it is a liturgical and communal act. This detail is theologically decisive: the experience of divine deliverance, rehearsed in the opening verses of Psalm 40, propels the recipient outward into the worshiping community.
Psalms 40:10 — "I have not hidden your righteousness within my heart"
The parallelism with verse 9 is antithetical in form but complementary in function: what verse 9 affirms positively (public proclamation), verse 10 negates (concealment). To hide righteousness "within the heart" would be to treat God's saving action as personal property, a private spiritual experience sealed from the community. The psalmist refuses this. The "heart" (lēb) in Hebrew anthropology is not merely the seat of emotion but of will, understanding, and decision. To not hide something in the heart is, paradoxically, to demonstrate that what lives in the heart has overflowed its banks and become public witness. The interior transformation and the exterior proclamation are inseparable.
Typological and Spiritual Senses
The Fathers of the Church, notably St. Augustine in his Enarrationes in Psalmos, read this psalm as spoken proleptically by Christ — the vox Christi — the voice of the Head speaking through the Body, the Church. On this reading, verse 9 is fulfilled preeminently in the public ministry of Jesus, who proclaimed the Kingdom of God — the definitive of the Father — in synagogues, on hillsides, and in the Temple courts. The "great assembly" becomes the totality of those who witness his ministry and, ultimately, the Church gathered at Eucharist. Verse 10, in its Christological reading, points to the perfect transparency of the Son: nothing of the Father's will was concealed, withheld, or domesticated. "I have made known to them your name," Jesus declares in John 17:26, echoing precisely this refusal to hide the Father's righteousness.