Psalms 21:1

The king shall joy - מלך משיחא melech Meshicha, "the King Messiah." - Targum. What a difference between ancient and modern heroes! The former acknowledged all to be of God, because they took care to have their quarrel rightly founded; the latter sing a Te Deum, pro forma, because they well know that their battle is not of the Lord. Their own vicious conduct sufficiently proves that they looked no higher than the arm of human strength. God suffers such for a time, but in the end he confounds and brings them to naught.

The king shall joy in thy strength - King David, who had achieved the victory which he had desired and prayed for, Psalm 20:1-9. This is in the third person, but the reference is doubtless to David himself, and is to be understood as his own language. If it be understood, however, as the language of "the people," it is still an ascription of praise to God for his favor to their king. It seems better, however, to regard it as the language of David himself. The word ""strength"" here implies that all the success referred to was to be traced to God. It was not by the prowess of a human arm; it was not by the valor or skill of the king himself; it was by the power of God alone.

And in thy salvation - In the salvation or deliverance from foes which thou hast granted, and in all that thou doest to save. The language would embrace all that God does to save his people.

How greatly shall he rejoice! - Not only does he rejoice now, but he ever will rejoice. It will be to him a constant joy. Salvation, now to us a source of comfort, will always be such; and when we once have evidence that God has interposed to save us, it is accompanied with the confident anticipation that this will continue to be the source of our highest joy forever.