Psalm 130 (De Profundis) is one of the seven penitential psalms that Catholic tradition has used for centuries in prayers for the dead and in personal confession. The Catechism cites this psalm in teaching about prayer from the depths of distress (CIC 2559). The opening cry—"Out of the depths I cry to you, O Lord"—expresses the human condition before God's mercy.
The Church prays this psalm in the Office of the Dead and at funerals, expressing hope in God's redemption even in the face of death. The verse "If you, O Lord, should mark iniquities, Lord, who could stand?" acknowledges universal sinfulness while affirming confidence in divine forgiveness. Catholic theology sees here the foundation for the doctrine of purgatory—the hope that God's mercy extends even beyond death.
The image of the watchman waiting for morning expresses the patient hope that characterizes Catholic spirituality. The Catechism teaches that hope is the theological virtue by which we await eternal life and the graces needed to attain it (CIC 1817-1821). This psalm teaches us to cry out to God from our deepest need, confident that His mercy is greater than our sin.