Psalms 18

Psalms 18:1  
I love You, O Jehovah, my strength.
18:2  
Jehovah is my crag and my fortress and my Deliverer; My God, my crock, in whom I take refuge; My shield and the horn of my salvation, my high retreat.
18:3  
I called upon Jehovah, who is worthy of praise, and from my enemies I was saved

Psalm 18 is a human talk with the divine God, implying David’s intimacy with God.

Psalms 18:20
Jehovah has recompensed me according to my righteousness; According to the cleanness of my hands He has repaid me

"recompensed"
In vv. 20-28 David considered his righteousness, perfection, faithfulness, cleanness, and purity as the cause of God’s saving him, and he considered God’s salvation a recompense to him. This is a wrong concept. God saves us not because of our righteousness but because of His mercy and His compassion (Lam. 3:22; Eph. 2:1-9; Titus 3:5) and because of His own purpose (2 Tim. 1:9).