Psalms 21:1

1. The king will rejoice in thy strength, O Jehovah! David could have given thanks to God in private for the victories and other signal favors which he had received from him; but it was his intention to testify not only that it was God who elevated him to the throne, but also that whatever blessings God had conferred upon him redounded to the public good, and the advantage of all the faithful. In the beginning of the psalm the believing Israelites express their firm persuasion that God, who had created David to be king, had undertaken to defend and maintain him. It therefore appears that this psalm, as well as the preceding, was composed for the purpose of assuring the faithful that the goodness of God in this respect towards David would be of long duration, and permanent; and it was necessary, in order to their being established in a well-grounded confidence of their safety; to hope well of their king, whose countenance was as it were a mirror of the merciful and reconciled countenance of God. The sense of the words is: Lord, in putting forth thy power to sustain and protect the king, thou wilt preserve him safe; and, ascribing his safety to thy power, he will greatly rejoice in thee. The Psalmist has doubtless put strength and salvation for strong and powerful succor; intimating, that the power of God in defending the king would be such as would preserve and protect him against all dangers.

In the second verse there is pointed out the cause of this joy. The cause was this: that God had heard the prayers of the king, and had liberally granted him whatever he desired. It was important to be known, and that the faithful should have it deeply impressed on their minds, that all David’s successes were so many benefits conferred upon him by God, and at the same time testimonies of his lawful calling. And David, there is no doubt, in speaking thus, testifies that he did not give loose reins to the desires of the flesh, and follow the mere impulse of his appetites like worldly men, who set their minds at one time upon this thing, and at another time upon that, without any consideration, and just as they are led by their sensual lusts; but that he had so bridled his affections as to desire nothing save what was good and lawful. According to the infirmity which is natural to men, he was, it is true, chargeable with some vices, and even fell shamefully on two occasions; but the habitual administration of his kingdom was such that it was easy to see that the Holy Spirit presided over it. But as by the Spirit of prophecy the Psalmist had principally an eye to Christ, who does not reign for his own advantage, but for ours, and whose desire is directed only to our salvation, we may gather hence the very profitable doctrine, that we need entertain no apprehension that God will reject our prayers in behalf of the church, since our heavenly King has gone before us in making intercession for her, so that in praying for her we are only endeavoring to follow his example.