John Calvin Commentary Psalms 72:4

"He will judge the poor of the people, He will save the children of the needy, And will break in pieces the oppressor." — Psalms 72:4 (ASV)

He shall judge the poor of the people. The poet continues his description of the end and fruit of a righteous government, and unfolds at greater length what he had briefly touched upon concerning the afflicted among the people. But it is a truth which ought to be kept 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.

As God had promised to extend His care to the poor and afflicted among His people, David, as an argument to reinforce the prayer which he presents on behalf of the king, shows that granting it will tend to the comfort of the poor. God is indeed no respecter of persons; but it is not without cause that God takes more special care of the poor than of others, since they are most exposed to injuries and violence.

If laws and the administration of justice are taken away, the consequence will be that the more powerful a man is, the more able he will be to oppress his poor brothers. David, therefore, particularly mentions that the king will be the defender of those who can only be safe under the protection of the magistrate, and declares that he will be their avenger when they are victimized by injustice and wrong.

The phrase, The children of the afflicted, stands for the afflicted, an idiom quite common in Hebrew, and a similar form of expression is sometimes used by the Greeks, as when they say υἱους ἰατρων, the sons of physicians, for physicians. But as the king cannot discharge the duty of succoring and defending the poor which David imposes upon him, unless he curbs the wicked by authority and the power of the sword, it is very justly added in the end of the verse, that when righteousness reigns, oppressors or extortioners will be broken in pieces. It would be foolish to wait until they should yield of their own accord.

They must be repressed by the sword, so that their audacity and wickedness may be prevented from proceeding to greater lengths. It is therefore requisite for a king to be a man of wisdom, and resolutely prepared to effectively restrain the violent and injurious, so that the rights of the meek and orderly may be preserved unimpaired.

Thus, no one will be fit for governing a people but he who has learned to be rigorous when the case requires. Licentiousness must necessarily prevail under an effeminate and inactive sovereign, or even under one who has a disposition that is too gentle and forbearing. There is much truth in the old saying, that it is worse to live under a prince through whose leniency everything is lawful, than under a tyrant where there is no liberty at all.