David having, as a preacher of the judgments of God, set forth the vengeance which God would take upon his enemies proceeds now, in the character of a prophet and teacher, to exhort the unbelieving to repentance, that they may not, when it is too late, be compelled to acknowledge, from dire experience, that the divine threatenings are neither idle nor ineffectual. And he addresses by name kings and rulers, who are not very easily brought to a submissive state of mind, and who are, besides, prevented from learning what is right by the foolish conceit of their own wisdom with which they are puffed up. And if David spare not even kings themselves, who seem unrestrained by laws, and exempted from ordinary rules, much more does his exhortation apply to the common class of men, in order that all, from the highest to the lowest, may humble themselves before God. By the adverb now, he signifies the necessity of their speedy repentance, since they will not always be favored with the like opportunity. Meanwhile, he tacitly gives them to understand, that it was for their advantage that he warned them, as there was yet room for repentance provided they made haste. When he enjoins them to be wise, he indirectly condemns their false confidence in their own wisdom as if he had said, The beginning of true wisdom is when a man lays aside his pride, and submits himself to the authority of Christ. Accordingly, however good an opinion the princes of the world may have of their own shrewdness, we may be sure they are arrant fools till they become humble scholars at the feet of Christ. Moreover, he declares the manner in which they were to be wise, by commanding them to serve the Lord with fear. By trusting to their elevated station, they flatter themselves that they are loosed from the laws which bind the rest of mankind; and the pride of this so greatly blinds them as to make them think it beneath them to submit even to God. The Psalmist therefore, tells them, that until they have learned to fear him, they are destitute of all right understanding. And certainly, since they are so much hardened by security as to withdraw their obedience from God, strong measures must at the first be employed to bring them to fear him, and thus to recover them from their rebelliousness. To prevent them from supposing that the service to which he calls them is grievous, he teaches them by the word rejoice how pleasant and desirable it is, since it furnishes matter of true gladness. But lest they should, according to their usual way, wax wanton, and, intoxicated with vain pleasures, imagine themselves happy while they are enemies to God, he exhorts them farther by the words with fear to an humble and dutiful submission. There is a great difference between the pleasant and cheerful state of a peaceful conscience, which the faithful enjoy in having the favor of God, whom they fear, and the unbridled insolence to which the wicked are carried, by contempt and forgetfulness of God. The language of the prophet, therefore, implies, that so long as the proud profligately rejoice in the gratification of the lusts of the flesh, they sport with their own destruction, while, on the contrary, the only true and salutary joy is that which arises from resting in the fear and reverence of God.