Matthew Henry on Psalms 7:1-9

David flees to God for succour. But Christ alone could call on Heaven to attest his uprightness in all things. All His works were wrought in righteousness; and the prince of this world found nothing whereof justly to accuse him. Yet for our sakes, submitting to be charged as guilty, he suffered all evils, but, being innocent, he triumphed over them all. The plea is, “For the righteous God trieth the hearts and the reins.” He knows the secret wickedness of the wicked, and how to bring it to an end; he is witness to the secret sincerity of the just, and has ways of establishing it. When a man has made peace with God about all his sins, upon the terms of grace and mercy, through the sacrifice of the Mediator, he may, in comparison with his enemies, appeal to God's justice to decide.