Praise him, ye heavens of heavens, and ye waters that be above the heavens.
Heavens of heavens — Ye highest heavens, the place of God's throne.
Waters — Ye clouds which are above a part of the heavens.

He hath also stablished them for ever and ever: he hath made a decree which shall not pass.
Established — He hath made them constant and incorruptible, not changeable, as the things of the lower world.
A decree — Concerning their continuance.

Praise the LORD from the earth, ye dragons, and all deeps:
Dragons — Either serpents, which hide in the deep caverns of the earth; or whales, and other sea-monsters, which dwell in the depths of the sea.

Fire, and hail; snow, and vapour; stormy wind fulfilling his word:
Fire — Lightnings and other fireworks of the air.
Vapour — Or, fumes: hot exhalations.
Fulfilling his word — Executing his commands, either for the comfort or punishment of the inhabitants of the earth.

Let them praise the name of the LORD: for his name alone is excellent; his glory is above the earth and heaven.
Above — Above all the glories which are in earth and in heaven.

He also exalteth the horn of his people, the praise of all his saints; even of the children of Israel, a people near unto him. Praise ye the LORD.
The horn — In scripture commonly denotes strength, victory, glory, and felicity.