“By the terms righteousness and judgment, the Psalmist means a due and well-regulated administration of government, which he opposes to the tyrannical and unbridled license of heathen kings, who, despising God, rule according to the dictates of their own will. . . . From the words we learn by the way, that no government in the world can be rightly managed but under the conduct of God, and by the guidance of the Holy Spirit. . . .But in requesting that the righteousness and judgment of God may be given to kings, he reminds them that none are fit for occupying that exalted station, except in so far as they are formed for it by the hand of God. . . . David teaches us that the people would enjoy prosperity and happiness, when the affairs of the nation were administered according to the principles of righteousness. . . . But it is a truth which ought to be borne in mind, that kings can keep themselves within the bounds of justice and equity only by the grace of God; for when they are not governed by the Spirit of righteousness proceeding from heaven, their government is converted into a system of tyranny and robbery.”
– John Calvin, Commentary on the Book of Psalms, trans. James Anderson, Calvin’s Commentaries, vol. 3 (Grand Rapids: Wm. B. Eerdmans Publishing Co., 1845 [reprinted 1948, 1963]), pp. 102, 103, 104-5.