Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
An exhortation to fear God.
Let us acknowledge God's power and goodness in what he did for Israel, applying it to that much greater work of wonder, our redemption by Christ; and encourage ourselves and others to trust in God in the greatest straits. When Christ comes for the salvation of his people, he redeems them from the power of sin and Satan, separates them from an ungodly world, forms them to be his people, and becomes their King. There is no sea, no Jordan, so deep, so broad, but, when God's time is come, it shall be divided and driven back. Apply this to the planting the Christian church in the world. What ailed Satan and his idolatries, that they trembled as they did? But especially apply it to the work of grace in the heart. What turns the stream in a regenerate soul? What affects the lusts and corruptions, that they fly back; that prejudices are removed, and the whole man becomes new? It is at the presence of God's Spirit. At the presence of the Lord, not only mountains, but the earth itself may well tremble, since it has lain under a curse for man's sin. As the Israelites were protected, so they were provided for by miracles; such was that fountain of waters into which the flinty rock was turned, and that rock was Christ. The Son of God, the Rock of ages, gave himself to death, to open a fountain to wash away sins, and to supply believers with waters of life and consolation; and they need not fear that any blessing is too great to expect from his love. But let sinners fear before their just and holy Judge. Let us now prepare to meet our God, that we may have boldness before him at his coming.