The psalmist, having taught his people to look back with joy and praise on what God had done for him and them, here teaches them to look forward with faith, and hope, and prayer, upon what God would further do for them: The king rejoices in God (Psa 21:1), and therefore we will be thankful; the king trusteth in God (Psa 21:7), therefore will we be encouraged. The joy and confidence of Christ our King is the ground of all our joy and confidence.

I.They are confident of the stability of David's kingdom. Through the mercy of the Most High, and not through his own merit or strength, he shall not be moved. His prosperous state shall not be disturbed; his faith and hope in God, which are the stay of his spirit, shall not be shaken. The mercy of the Most High (the divine goodness, power, and dominion) is enough to secure our happiness, and therefore our trust in that mercy should be enough to silence all our fears. God being at Christ's right hand in his sufferings (Psa 16:8) and he being at God's right hand in his glory, we may be sure he shall not, he cannot, be moved, but continues ever.

II.They are confident of the destruction of all the impenitent implacable enemies of David's kingdom. The success with which God had blessed David's arms hitherto was an earnest of the rest which God would give him from all his enemies round about, and a type of the total overthrow of all Christ's enemies who would not have him to reign over them. Observe, 1. The description of his enemies. They are such as hate him, Psa 21:8. They hated David because God had set him apart for himself, hated Christ because they hated the light; but both were hated without any just cause, and in both God was hated, Joh 15:23, Joh 15:25. 2. The designs of his enemies (Psa 21:11): They intended evil against thee, and imagined a mischievous device; they pretended to fight against David only, but their enmity was against God himself. Those that aimed to un-king David aimed, in effect, to un-God Jehovah. What is devised and designed against religion, and against the instruments God raises up to support and advance it, is very evil and mischievous, and God takes it as devised and designed against himself and will so reckon for it. (3.) The disappointment of them: "They devise what they are not able to perform," Psa 21:11. Their malice is impotent, and they imagine a vain thing, Psa 2:1. (4.) The discovery of them (Psa 21:8): "Thy hand shall find them out. Though ever so artfully disguised by the pretences and professions of friendship, though mingled with the faithful subjects of this kingdom and hardly to be distinguished from them, though flying from justice and absconding in their close places, yet thy hand shall find them out wherever they are." There is no escaping God's avenging eye, no going out of the reach of his hand; rocks and mountains will be no better shelter at last than fig-leaves were at first. (5.) The destruction of them; it will be an utter destruction (Luk 19:27); they shall be swallowed up and devoured, Psa 21:9. Hell, the portion of all Christ's enemies, is the complete misery both of body and soul. Their fruit and their seed shall be destroyed, Psa 21:10. The enemies of God's kingdom, in every age, shall fall under the same doom, and the whole generation of them will at last be rooted out, and all opposing rule, principality, and power, shall be put down. The arrows of God's wrath shall confound them and put them to flight, being levelled at the face of them, Psa 21:12. That will be the lot of daring enemies that face God. The fire of God's wrath will consume them (Psa 21:9); they shall not only be cast into a furnace of fire (Mat 13:42), but he shall make them themselves as a fiery oven or furnace; they shall be their own tormentors; the reflections and terrors of their own consciences will be their hell. Those that might have had Christ to rule and save them, but rejected him and fought against him, shall find that even the remembrance of that will be enough to make them, to eternity, a fiery oven to themselves: it is the worm that dies not.

III.In this confidence they beg of God that he would still appear for his anointed (Psa 21:13), that he would act for him in his own strength, by the immediate operations of his power as Lord of hosts and Father of spirits, making little use of means and instruments. And, 1. Hereby he would exalt himself and glorify his own name. "We have but little strength, and are not so active for thee as we should be, which is our shame; Lord, take the work into thy own hands, do it, without us, and it will be thy glory." 2. Hereupon they would exalt him: "So will we sing, and praise thy power, the more triumphantly." The less God has of our service when a deliverance is in the working the more he must have of our praises when it is wrought without us.

For the King trusteth in the Lord,.... That is, the King Messiah, as the Targum paraphrases it; he trusted in the Lord for his support and sustenance as man, for assistance and help in his time of trouble, and for deliverance out of it; he trusted in the Lord that he would hear him for himself, and for his people; and that he would glorify him with all glory, honour, majesty, and blessedness, before spoken of; see Psa 22:8;

and through the mercy of the most High he shall not be moved; God the Father is the most High; Christ is called the Son of the Highest, and the Spirit the power of the Highest, Luk 1:32; there is mercy with him, which is a ground of hope and trust, in his people, and also in the Messiah; see Psa 89:28; and some versions make the mercy of the most High to be what the King Messiah trusts in, reading the words (b), "for the King trusteth in the Lord, and in the mercy of the most High"; but the accent "athnach", which distinguishes the propositions, will not admit of it; but the sense is, that because of the mercy, grace, goodness, and faithfulness of God in making and keeping his promises, Christ would not be and was not moved from his trust and confidence in the Lord; nor shall he even be removed from his throne of glory on which he sits; nor from the glorious and happy state in which he is: nor will it ever be in the power of his enemies to displace him; for these in time will be destroyed by him, as the following words show.

(b) So Genebrard, Muis,

For thou hast made him most blessed for ever,.... Not as God, for as such he is over all blessed for ever, and not made so; but as man and Mediator; the words may be rendered, "thou hast set him to be blessings for ever" (z); which design the blessings which are laid up in Christ for his people, and which he imparts unto, them, and they are blessed with in him; so that he is made a blessing, or rather blessings to them; such as redemption to free them from, bondage, righteousness to justify them, sanctification to make them holy, wisdom to direct and guide them, and strength to assist and support them; through whom they have the forgiveness of sins, by whom they have peace with God, and from whom they receive all their joy and comfort, and at last eternal life and happiness; and all these are for ever, they are irreversible blessings, are never repented of, nor taken away: or this blessedness may be understood of that which Christ himself enjoys as man; which lies in his human nature being exalted to union with the Son of God; in being heard and helped in the day of salvation; in being raised from the dead, and glory given him; in being set at God's right hand, angels, authorities, and powers, being subject to him; and in seeing the travail of his soul with satisfaction: the particular instance of his blessedness follows;

thou hast made him exceeding glad with thy countenance; the glorious presence of God in heaven; Christ having done his work on earth ascended to heaven, where he was received by his Father with a cheerful countenance, was made to sit down on the same throne with him, being well pleased with his obedience, righteousness, and sacrifice; and being now in the presence of God, in which is fulness of joy, and at his right hand, where are pleasures for evermore, the human nature of Christ is filled with an excess of joy; the words may be rendered, "thou hast made" or "wilt make him glad with joy (a), with thy countenance"; see Psa 16:11.

(z) "posuisti vel pones eum benedictiones", Pagninus, Montanus, Vatablus; so Ainsworth, Cocceius, Gejerus. (a) "laetificabis eum in laetitia", Pagninus, Montanus, Michaelis; so Junius & Tremellius, Gejerus.

Next: Psalms Chapter 22

The mediate cause is the king's faith, the efficient, God's mercy.