Praise him, ye heavens of heavens - Referring to the idea that there is one heaven rising above another. See the notes at Psalm 68:33. See 1-Kings 8:27 : "Behold, the heaven and heaven of heavens cannot contain thee." Compare 2-Chronicles 2:6.
And ye waters that be above the heavens - Genesis 1:7 : "And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament." The allusion here is to the waters which seem to be above the lower heaven, that is, the air, and which seem to come from some higher region - some higher heaven. See the notes at Psalm 104:3 : "Who layeth the beams of his chambers in the waters."

Heavens of heavens - Heavens exceeding heavens. Systems of systems extending as far beyond the solar system, as it does beyond the lowest deeps. The endless systematic concatenation of worlds.
Ye waters that be above the heavens - This refers to Genesis 1:7 (note), where see the notes. Clouds, vapours, air, exhalations, rain, Snow, and meteors of every kind.

Praise him, ye (c) heavens of heavens, and ye (d) waters that [be] above the heavens.
(c) Not that there are various heavens, but because of the spheres and of the situation of the fixed stars and planets, he comprehends by this word the whole heavens.
(d) That is, the rain which is in the middle region of the air, which he here comprehends under the name of the heavens.

Praise him, ye heaven of heavens,.... All the heavens, the airy and starry heavens; and the third heaven, the residence of God, angels and saints: these are made by the Lord, and declare the glory of his power, wisdom, and goodness, and show forth his handiwork, Psalm 19:1. A voice was heard from heaven, praising Jehovah the Son, when on earth in our nature; a cloud of the lower heavens received him when he went from hence, and in the clouds thereof he will come again: the highest heavens opened to receive him, and will retain him until the restitution of all things; and from hence he will descend to judge the world in righteousness, Matthew 3:16;
and ye waters that be above the heavens; divided by the firmament from the waters below; and are no other than the thick clouds, in which the waters are bound up, and not rent, but at the pleasure of God, Genesis 1:7; so Seneca (d) calls the clouds the celestial waters. And these give men occasion to praise the Lord, that those vast bodies of water that are over their heads are not let down in such large quantities upon them as would destroy them; and that are carried about from place to place, and let down and gentle showers, to water and refresh the earth, and make it fruitful, so that it brings forth food for man and beast. The Targum is,
"ye waters, that by the Word (of the Lord) hang above the heavens;''
in which is displayed the glory of amazing power, wisdom, and goodness. The most ancient Syrians and Arabians were thoroughly persuaded, that beyond the bounds of the visible heavens there was a great sea, without any limits; which some (e) suppose to be the waters here meant.
(d) Nat. Quaest. l. 3. c. 23. (e) Vid. Steeb. Coelum Sephirot. Hebrews. c. 7. s. 3. p. 126, 127. and Gregory's Works, p. 110.

heavens of heavens--the very highest.
waters--clouds, resting above the visible heavens (compare Genesis 1:7).

Heavens of heavens - Ye highest heavens, the place of God's throne. Waters - Ye clouds which are above a part of the heavens.