Out of the depths I cry to you, O LORD! O Lord, hear my voice! Let your ears be attentive to the voice of my pleas for mercy!
Psalm 130:1-2 (ESV)
The 130th psalm is a psalm of prayer that comes from genuine Davidic devotion and understanding. It confesses that before God no one is righteous, nor may one become righteous by his own work and righteousness, but only through grace and forgiveness of sins, which God has promised. The psalmist comforts himself. as he relies on this promise and Word. He exhorts all of Israel that they should do the same and learn that with God is a throne of grace and redemption. Through Him alone and no way else shall Israel be freed of sins, that is, “through forgiveness” (without which there is no grace) become righteous and blessed. Apart from this, he truly would be in the depths and would never stand before God.
Look! The true master and doctor of the Holy Scriptures is the one who understands what this means. The seed of the woman shall tread on the head of the serpent (Genesis 3:15), and through this seed all the nations of the world shall be blessed (Genesis 12:30). Therefore, the psalmist places both a promise and a prophecy of Christ in this verse: “He will redeem Israel from all his iniquities (Psalm 130:8).” Upon this verse, and from it, comes the entire psalm.
God, our Father, who is rich in mercy and with whom is plenteous forgiveness, remember not the sins of our youth, nor our transgressions. Blot them out for the sake of Jesus Christ, Your beloved Son, who became the sacrifice for our sins. For the sake of His crimson blood let our sins be forgotten, and let them be imputed to us no more. Amen.
(from “Reading the Psalms with Luther”, pgs. 314-316)