Charles H. Spurgeon on Psalms 119:121

I have done judgment and justice. This was a great thing for an Eastern ruler to say at any time, for these despots mostly cared more far gain than justice. Some of them altogether neglected their duty, and would not even do judgment at all, preferring their pleasures to their duties; and many more of them sold their judgments to the highest bidders by taking bribes, or regarding the persons of men. Some rulers gave neither judgment nor justice, others gave judgment without justice, but David gave judgment and justice, and saw that his sentences were carried out. He could claim before the Lord that he had dealt out even handed justice, and was doing so still. On this fact he founded a plea with which he backed the prayer "Leave me not to mine oppressors." He who, as far as his power goes, has been doing right, may hope to be delivered from his superiors when attempts are made by them to do him wrong. If I will not oppress others, I may hopefully pray that others may not oppress me. A course of upright conduct is one which gives us boldness in appealing to the Great Judge for deliverance from the injustice of others. Nor is this kind of pleading to be censured as self righteous: when we are dealing with God as to our shortcomings, we use a very different tone from that with which we face the censures of our fellow men; when they are in the question, and we are guiltless towards them, we are justified in pleading our innocence.