¹O Lord, in Your strength the king will be glad, and in Your salvation how greatly he will rejoice! ²You have given him his heart’s desire, and You have not withheld the request of his lips. Selah.

This psalm closely aligns with the previous one, Psalm 20. Whereas the former is a prayer asking for victory, this one reflects the answer to that prayer. Both have to do with the king; here David refers to himself in the second person. Verses 1–2 are the expression of David’s joy in having his prayer answered. What was asked for in the previous psalm, David rejoices that God has now answered and given him “his heart’s desire” (Ps. 20:4, 21:2). This is an example of the principle David wrote about in another psalm, “Delight yourself in the Lord; and He will give you the desires of your heart” (Ps. 37:4). David delighted in the things that delight God. As the Lord’s anointed king, his prayer for deliverance was God’s will.

By contrast, King Solomon, the successor to David’s throne, warns about desiring the wrong things. He wrote about the temptation to adultery, “Do not desire her beauty in your heart, nor let her capture you with her eyelids” (Prov. 6:25). Solomon failed in keeping his own advice by his own confession:

“All that my eyes desired I did not refuse them. I did not withhold my heart from any pleasure, for my heart was pleased because of all my labor and this was my reward for all my labor. Thus I considered all my activities which my hands had done and the labor which I had exerted, and behold all was vanity and striving after wind and there was no profit under the sun.” (Eccl. 2:10–11)

David’s prayer, in contrast, was a godly desire, and therefore he was rejoicing in the Lord’s goodness to him.

In verses 3–6, he rehearses his overwhelming blessing from God. In verse 4, he tells of the long life he is promised: “You asked life of Him, He gave it to you, length of days, forever and ever.” Often in the OT, we find hyperbole used to express a long period of time as “forever.” But, if this psalm (and the previous ones) is applied to the King who was yet to come, namely Jesus, then the application is literal. For those who want to delve deeper into this, consider how the writer of Hebrews, in identifying Jesus as a Melchizedekian priest, described Him: “Without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, he remains a priest perpetually” (Heb 7:3).

In verses 7-10 of Psalm 21, the king expresses unshakable confidence in the Lord’s retribution against his adversaries. Today, the actions that David anticipated God would perform seem rather barbaric, violent things to rejoice in. But the times were violent, with no rules of law, no Geneva Convention. David’s wars would be what we would call “just” wars, with nations and adversaries who were trying to snuff out Israel. Peace treaties were not an option. God was going to bring judgment through David and on David’s behalf.

David concludes his praise psalm with final exultation: “Be exalted, O Lord, in Your strength; we will sing and praise Your power” (Ps 21:13). His confidence led to praise.

The Lord Jesus affirmed the confidence we can have in prayer, as we learn through the apostle John’s writings:

“Whatever you ask in My name, that will I do, so that the Father may be glorified in the Son. “If you ask Me anything in My name, I will do it.” (John 14:13–14)

“If you abide in Me, and My words abide in you, ask whatever you wish, and it will be done for you.” (John 15:7)

This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. (1 John 5:14)

Lord, thank You for the many answers to prayers You have given me. I am confident that You will act on my behalf in the future.