John Calvin Commentary Psalms 72:2

"He will judge thy people with righteousness, And thy poor with justice." — Psalms 72:2 (ASV)

He shall judge your people in righteousness. Some read this in the form of a wish—O that he may judge, etc. Others retain the future tense, and thus it is a prophecy. But we will come nearer the correct interpretation by understanding something intermediate as implied. All that is afterward spoken concerning the king flows from the supposition that the blessing prayed for in the first verse is conferred on him—from the supposition that he is adorned with righteousness and judgment.

The prayer, then, should be explained thus: Govern our king, O God! that he may judge. Or in this way: When you shall have bestowed on the king your righteousness, then he will judge uprightly. To govern a nation well is an endowment far too excellent to grow out of the earth; but the spiritual government of Christ, by which all things are restored to perfect order, should much more be considered a gift of heaven.

In the first clause of the verse, David speaks of the whole people in general. In the second clause, he expressly mentions the poor, who, on account of their poverty and weakness, need the help of others, and for whose sake kings are armed with the sword to grant them redress when unjustly oppressed.

Hence, also, proceeds peace, of which mention is made in the third verse. The term peace being employed among the Hebrews to denote not only rest and tranquillity, but also prosperity, 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.

The bringing forth of peace is a figurative expression taken from the fertility of the earth. And when it is said that the mountains and hills shall bring forth peace, the meaning is that no corner of the country would be found where it did not prevail. This includes even the most unpromising parts, indicated by the mountains, which are commonly barren or at least do not produce as great an abundance of fruit as the valleys.

Besides, both the word peace and the word righteousness are connected with each clause of the verse and must be twice repeated, the idea conveyed being that peace through righteousness should be diffused through every part of the world. Some read simply righteousness, instead of In righteousness, supposing the letter ב (beth) to be redundant here, which does not, however, appear to be the case.