“God is in the midst of her; she shall not be moved; God will help her when morning dawns” (Psalm 46:5 ESV). The word, “moved” (Heb. mot) is the same word for “move” in v. 2. The mountains are moved, but Jerusalem shall not be moved. In v. 6, the word, “rage” (Heb. hamar), is the same word for the word, “roar” in v. 3. As the waters roar, the nations rage.
Thus, nature is like the nations. As the mountains move, so do the nations. As the waters roar, so do the nations. Yet the object of their raging is Jerusalem.
“The nations rage, the kingdoms totter; he utters his voice, the earth melts” (Psalm 46:6 ESV). The nations rage, the kingdoms shake. But the voice of God shall overcome the raging of the nations and the shaking of the kingdoms. The voice of God shall melt the earth. The voice of God shall destroy the nations.
No wonder that the psalmists can say in v. 7, “The Lord of hosts is with us; the God of Jacob is our fortress.”
 Donald Williams, Psalms 1-72 (ed. Lloyed J. Ojilvie; TPCS 13; Nashville: Thomas Nelson, 1986), 357.