Psalms 148:9

Mountains, and all hills. — The invocation now alights on the crests of the highest mountains, and passes downward to the lower hills where vegetable life begins.

Fruitful trees. — Rather, fruit trees; the fruit-bearing tree being representative of one division of the vegetable world, planted and reared by man, the cedars of the other, which are (Psalms 104:16) of God’s own plantation.