The LORD is King for ever and ever: the heathen are perished out of his land.
Does this sentence point back to the great instance of exterminating justice in the destruction of the Canaanite? It may do so, but it is rather to be taken as referring to the victories celebrated in the previous and companion Psalm. Note the recurrence of the words "nations" and "perished," which are drawn from it. The connection between the two Psalms is thus witnessed, and the deliverance from foreign enemies, which is the theme of Psalm 9, is urged as a plea with God, and taken as a ground of confidence by the Psalmist himself for the completion of the deliverance by making domestic oppressors powerless. This lofty height of faith is preserved in the closing stanza, in which the agitation of the first part and the yearning of the second are calmed into serene assurance that the Ecclesia pressa has not cried, and never can cry, in vain. Into the praying, trusting heart "the peace of God which passeth understanding" steals, and the answer is certified to faith long before it is manifest to sense. To pray and immediately to feel the thrilling consciousness "Thou hast heard," is given to those who pray in faith. The wicked makes a boast of his "desire"; the humble makes a prayer of it, and so has it fulfilled. Desires which can be translated into petitions will be converted into fruition....The prayer of the humble, like a whisper amid the avalanches, has power to start the swift, white destruction on its downward path; and when once that gliding mass has way on it, nothing which it smites can stand.
(A. Maclaren, D. D.)
Parallel VersesKJV: The LORD is King for ever and ever: the heathen are perished out of his land.