Which by his strength setteth fast the mountains,.... In the first creation and formation of them, when they were settled on their basis so firmly that they are rarely removed, and when they are it is something extraordinary. Some understand this of the Lord's preparing the mountains with the rain of his strength, for the bringing forth of herbs and grass for the service of man and beast, and of his adorning them with trees; and the Targum is, "who preparest food for the wild goats of the mountains;'' others interpret them of kingdoms and communities, comparable to mountains, Jer 51:25; but these are not set fast, they are not firm and stable, but in a course of time are removed, and give way to others; rather the church of God is meant; see Isa 2:2; where the same phrase is used as here; and "mountains" may signify particular churches, or indeed particular believers; for all that trust in the Lord are like to mountains, Psa 125:1; and these are set fast in the everlasting love of God, by which their mountain is made to stand strong; in eternal election, which is the foundation of God that stands sure; in the covenant of grace, which is more immovable than hills and mountains; and on Christ the Rock, against whom the gates of hell can never prevail; and who are so established, settled, and kept by the power of God, that they cannot be removed by the most boisterous storms and winds of the world's persecutions, Satan's temptations, or their own sins and corruptions; being girded with power: not the mountains, but God himself; whose power, like himself, is infinite, and appears in the works of his hands, of nature, providence, and grace: the allusion is to a mighty man girded for battle; or for the performance of great undertakings.