Having preached to his enemies to repent and believe, he now quotes their words of unbelief. This further underscore their inability to repent and believe. This is the content of the thoughts of their hearts. There is no human way for man to turn from his raging against God and toward God in humble faith: This must be wrought in the heart by the supernatural working of the Holy Spirit. Hence, David next says
6a. Lift up the light of Your face upon us, O Lord!
Why? For it is only in God’s light that man sees light.1 And it is only the Lord God who can shed light upon man’s darkened heart. The apostle Paul explains that
God, who said, “Let light shine out of darkness,” has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ.2
David is not as specific as Paul, but he nonetheless recognizes the same fact: God must cause His blessing of the light of the Gospel to fall upon and light the eyes of those who are blinded by their sins. The Lord must shine upon them and cause them to see His goodness toward them, their rebellion and guilt toward Him, and that the sins of all who trust in Him and the sacrifice He has provided for them will receive pardon and goodness from Him. David’s allusion to Numbers 6:25, moreover, seems to underscore this as well, stating: “the LORD make his face to shine upon you and be gracious to you.”
In this one petition we are told who it is that makes man a new creature by means of the light of His grace and truth: Yahweh, our Lord and Savior. It is no wonder that John, therefore, writes:
The true light, which gives light to everyone, was coming into the world. He was in the world, and the world was made through him, yet the world did not know him. He came to his own, and his own people did not receive him. But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.
And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.3
1cf. Ps 36:9b
22 Cor 4:6
3John 1:9-14 (emphasis added)