In the following article you will find a brief commentary on Psalm 7 that goes along with our Riverside Church Two Year Bible Reading Plan (Volume 1 & Volume 2). This plan will allow you to read the New Testament and Psalms once every year and the Old Testament once every two years.
A Good Conscience
By A. J. Motyer:
We do not know who Cush was but we do know that Saul, the Benjamite king (1 Sa. 9:1), surrounded himself with Benjamites (1 Sa. 22:7); also that he was incited against David by slandering tongues (1 Sa. 24:9; 26:19). A situation like 1 Samuel 18:10–24 would have given plenty of scope for the ‘Cushes’ of this world to inflame Saul’s paranoiac dread of David. But David knew that no accusation of disloyalty against Saul was true; even before God’s judgment seat (6, 7, 10–13), his conscience was clear (8b, 9) and these verses are the heart of the psalm and a summons to preserve in all things ‘a conscience as the noonday clear’ (Acts 24:16; Heb. 13:18; 1 Pet. 3:16).
 Carson, D. A., France, R. T., Motyer, J. A., & Wenham, G. J. (Eds.). (1994). New Bible commentary: 21st century edition (4th ed., p. 491). Leicester, England; Downers Grove, IL: Inter-Varsity Press.