New Defender's Study Bible Notes
148:4 heaven of heavens. Psalm 148:1-6 of this central psalm of these five praise psalms exhorts the entire celestial creation, both the stellar and angelic hosts of heaven, to praise the Lord when He has redeemed and restored the creation.
148:4 above the heavens. The “waters above the heavens” (Genesis 1:7) were presumably all precipitated at the time of the Flood. But since they are to be there forever (Psalm 148:6), they must be restored somehow in the redeemed and renewed earth. See notes on Revelation 21, etc.