Praise him, ye heavens of heavens, and ye waters that be above the heavens.
Praise him, ye heavens of heavens - the highest heavens: as "holy of holies" is in Hebrew idiom the superlative, "the most holy place" (1 Kings 8:27; Deuteronomy 10:14). Compare the parallel history, Nehemiah 9:6. So 2 Corinthians 12:2 alludes to a gradation in height of the several heavens - "the third heaven." The angels, the stars, and the clouds (Psalms 148:2-4) imply successive regions above.
And ye waters that (be) above the heavens - the clouds, the lowest heavens, in contrast to the "heavens of heavens," the highest (Genesis 1:7; Psalms 104:3). Those called to praise the Lord are six, answering to the number of verses in the first half strophe.