My defence is of God, which saveth the upright in heart.
David protested his innocence before God because his conscience did not accuse him of the wickedness laid to his charge. He committed his case to the Divine protection, reflecting on God's goodness and righteousness, assured that the vain attempts of his enemies would turn to their own destruction.
AI summary
Commenting on Psalm 7:1-17
The judge has heard the cause, has cleared the guiltless, and uttered his voice against the persecutors. Let us draw near, and learn the results of the great assize. Yonder is the slandered one with his harp in hand, hymning the justice of his Lord, and rejoicing aloud in his own deliverance.
David having lodged his appeal with God by prayer and a solemn profession of his integrity, in the former part of the psalm, in this latter part does, as it were, take out judgment upon the appeal, by faith in the word of God, and the assurance it gives of the happiness and safety of the righteous and the certain destruction of wicked people that continue impenitent. I.
Commenting on Psalm 7:10-17