Psalms 89:22

22 The enemy shall not exact upon him. Here it is declared in express terms, that although David may not be without enemies, the power of God will be always ready to maintain and defend him, that he may not be oppressed with unrighteous violence. It is accordingly affirmed, that David will not be tributary to his enemies, as he who is vanquished in battle is constrained to grant such conditions of peace as his conqueror may dictate, however injurious to himself these may be. When his enemies are called sons of iniquity, it is tacitly intimated, that this government will be so exempt from tyranny and extortion, that whoever shall attempt to overthrow it will be involved in the perpetration of wrong and wickedness. The amount is, that David and his successors will be so secure and strongly fortified by the divine protection, that it will be impossible for their enemies to treat them as they would wish. In regard to the fact, that God suffered this kingdom to be greatly afflicted, so that David’s successors were constrained to pay a vast amount of tribute to foreign and heathen kings, it is not at variance with this promise; for, although the power of the kingdom was reduced, it was enough that the root still remained, until Christ came, in whose hand the kingdom was at length firmly established. As both the king and the people wickedly rejected this singular blessing of God, the kingdom was often shaken through their own default, afterwards impaired, and finally ruined. Yet God, to confirm his oracle concerning the perpetuity of this kingdom, ceased not all along to cherish and preserve some hope, by contending against their ingratitude. Besides, when mention is made of David’s haters and oppressors, it is intimated, that this throne will not be privileged with exemption from annoyances and troubles, inasmuch as there will be always some who will rise up in hostility against it, unless God set himself in opposition to them.