“Hear a just cause, O Lord; attend to my cry! Give ear to my prayer from lips free of deceit!” -Psalm 17:1
David begins with proclaiming his cause or position against his enemies as just. This is not based on feelings or a personal subjective vendetta, as that would be a futile case to bring before the omniscient Judge of the universe. His cause is just and his petition is truthful, free of deceit.
As John Calvin notes, “David, confiding in his own integrity, interposes God as a Judge between himself and his enemies, to cognosce or determine in his cause.”
What does this mean for us? Many lessons can be inferred, but an important one to consider is what the Psalmist says in Psalm 84; “For the Lord God is a sun and shield; the Lord bestows favor and honor. No good thing does he withhold from those who walk uprightly” (Psalm 84:11).
David’s confidence is rooted in his own alignment and submission to God’s law. It’s important to remember, as we consider this essential aspect of prayer and invoking God’s intervention, that David is not claiming he is not a sinner at all. He is simply proclaiming his righteousness in the matter at hand, and alignment with God’s law generally speaking. For the believer, we have even more confidence because of Christ.
“For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need.” -Hebrews 4:15–16
Though our standing before God is righteous because of Christ, it is even more reason that our petitions against our enemies be always just and requested with lips free from deceit.