Verse 7 is the essence of salvation. First is the prayer of repentance. We will only be rescued if the Lord will forgive. But there is still a question of how does the Lord now think of us? I am forgiven, but that doesn’t make me righteous. Therefore, the psalmist continues with the prayer that the Lord would remember him according to His steadfast love. The words steadfast love almost always refer to the covenant promise of God. The psalmist is basically asking that the Lord would remember him according to how the Lord has promised to save Him. So he is not only forgiven, but considered righteous according to the covenant love of God.
This psalm is precious because it so humbly acknowledges the twin sufferings of every believer. Yes, he has enemies. Yes, he needs rescue from the traps that have been set for him. But he is also, himself, a sinner. His request is that he would be rescued from the foe, but also that the Lord would guard his soul against sin so that he would not be put to shame.
All of this is according to the steadfast love of the Lord and for the Lord’s namesake.
Verse 19 and verse 21 are perfect complements for one another. We are warned that we should be cautious about the use of many words, but we are also told that words have the power to do great good. The righteous will learn to measure his words to do good for the sake of others.