For the LORD most high is terrible; he is a great King over all the earth.
For the Lord most high is terrible - the ground of exultation, namely, Yahweh's interposition for His people with terrible judgments on their enemies (Psalms 68:35).
He is a great King over all the earth. The destruction of Israel's last foes shall be the preliminary to His manifestation as "King over all the earth." Every previous triumph of God's people is an earnest of the final one.