The Fair Judge
He judges the world with righteousness, He judges the peoples with equity.
PSALM 9:8 (RSV)
The Fair Judge
Equity and justice are generally distinguished in the Scriptures in this way, that equity looks to persons while justice deals with causes. He is fair (equus) who is the same toward all and conducts himself fairly, and neither by hatred nor by love, neither by riches nor by poverty is he influenced in favor of one more than of another. Thus God is called fair, because He sets forth His grace not only to the Jews but without discrimination to all men . . . for He is the same for all, of the same severity and leniency, and for no one more or less [for the rich man as for the poor man, for the Jew as for the Gentiles]. Human laws, however, are often like "webs of a spider" (Isaiah 59:5f.) and unfair. . .. "Justice," however, is said to be the restoration to each one of what belongs to him. Hence equity comes before justice and is, as it were, the prerequisite. And equity distinguishes merits, while justice returns reward. Thus the Lord "judges the world in equity" (for He is the same for all, He desires all to be saved), and He "judges in justice" (Psalm 98:9), because He gives to each one his own reward. An example of both is in the Gospel parable, where after the individuals had received the day's wage, some complained about unfairness (Matthew 20:10-12).
From First Lectures on the Psalms, on Psalm 9, commenting on the Latin translation of this verse (Luther's Works 10:94-95)