John Calvin Commentary Psalms 20:9

"Save, Jehovah: Let the King answer us when we call." — Psalms 20:9 (ASV)

Save, O Jehovah! and so forth. Some read in one sentence, O Jehovah! save the king; perhaps because they think it is wrong to attribute to an earthly king what is proper to God only—to be called upon, and to hear prayer. But if we turn our eyes toward Christ, as we should, we will no longer wonder that what properly belongs to Him is attributed in a certain sense to David and his successors, insofar as they were types of Christ. As God governs and saves us by the hand of Christ, we must not look for salvation from any other source. In the same way, the faithful under the former dispensation were accustomed to turn to their king as the minister of God’s saving grace. Hence these words of Jeremiah:

The breath of our nostrils, the anointed of the Lord, of whom we said, Under his shadow we shall live among the heathen (Lamentations 4:20).

Whenever, therefore, God promises the restoration of His church, He presents a symbol or pledge of its salvation in the kingdom. We now see that it is not without very good reason that the faithful are introduced asking for help from their king, under whose guardianship and protection they were placed, and who, as the vicegerent of God, presided over them. As the Prophet Micah says, Their king shall pass before them, and the Lord on the head of them (Micah 2:13); by these words he intimates that their king will be, as it were, a mirror in which they may see reflected the image of God.

To return to the present passage: The expression, Save, O Jehovah, is elliptical, but it has greater emphasis than if the object for which salvation is sought had been mentioned; for by this means David shows that this salvation belongs in common to the whole body of the church. In Psalm 118:25, there is a prayer in the same words, and it is certain that it is the very same prayer.

In short, this is a prayer that God, by blessing the king, would show Himself the Savior of the whole people. In the last clause of the verse, the means of this salvation are expressed. The people pray that the king may be equipped with power from God to deliver them whenever they are in distress and cry to him for help.

Let the king hear us in the day that we call upon him. God had not promised that His people would be saved in any other way than by the agency and leadership of the king whom He had given them. In the present day, when Christ is now manifested to us, let us learn to yield Him this honor—to renounce all hope of salvation from any other source, and to trust only in that salvation which He shall bring to us from God His Father.

And we shall only then become partakers of this when, being all gathered together into one body under the same Head, we shall have mutual care for one another, and when none of us will have his attention so engrossed with his own advantage and individual interest as to be indifferent to the welfare and happiness of others.