Chapter 04 - Of Heaven

Heaven is like a roof to the material world, and will serve as the floor of the new world. It is by nature shining and glorious, and is the dwelling-place of the invisible hosts. When God spread out this firmament, He brought up above it a third part of the waters, and above these is the heaven of light and of the luminaries. 

Hence people say 'the heaven, and the heaven of heavens;’ for we call both the firmament and the waters which are above it 'heaven.' 

Some consider that the verse 'Let the waters which are above the heavens praise the name of the Lord' refers to the holy angels and to our Lord's humanity; but neither the Church nor the orthodox teachers accept this.