Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
This psalm is a prayer for the kings of Israel, but with relation to Christ.
Even the greatest of men may be much in trouble. Neither the crown on the king's head, nor the grace in his heart, would make him free from trouble. Even the greatest of men must be much in prayer. Let none expect benefit by the prayers of the church, or their friends, who are capable of praying for themselves, yet neglect it. Pray that God would protect his person, and preserve his life. That God would enable him to go on in his undertakings for the public good. We may know that God accepts our spiritual sacrifices, if by his Spirit he kindles in our souls a holy fire of piety and love to God. Also, that the Lord would crown his enterprises with success. Our first step to victory in spiritual warfare is to trust only in the mercy and grace of God; all who trust in themselves will soon be cast down. Believers triumph in God, and his revelation of himself to them, by which they distinguish themselves from those that live without God in the world. Those who make God and his name their praise, may make God and his name their trust. This was the case when the pride and power of Jewish unbelief, and pagan idolatry, fell before the sermons and lives of the humble believers in Jesus. This is the case in every conflict with our spiritual enemies, when we engage them in the name, the spirit, and the power of Christ; and this will be the case at the last day, when the world, with the prince of it, shall be brought down and fall; but believers, risen-from the dead, through the resurrection of the Lord, shall stand, and sing his praises in heaven. In Christ's salvation let us rejoice; and set up our banners in the name of the Lord our God, assured that by the saving strength of his right hand we shall be conquerors over every enemy.