Charles H. Spurgeon on Psalms 97:5

The hills melted like wax at the presence of the LORD. For a parallel passage see Mic 1:4. There the words are applied to the judgment of God about to fall on the people of the covenant: here they are applied to the judgment on the God opposing world. The fact that judgment has begun at the house of God is a token that judgments of a far more destructive kind will overtake the (openly) ungodly and sinners (1Pe 4:7). "The hills" symbolize the heights or man's self exalting pride of intellect, wealth, and power. —A.R. Faussett.