The scriptural content for this post is found in Genesis 1:6-9
There was initially the liquid water covering the earth and also water above the earth as vapor or cloud. This cloud occupied the entire atmosphere from the surface of the liquid water up throughout the atmosphere. This vapor was thin enough for the defused light to be perceived on the earth but would have hindered the ability for the landscape to be illuminated and for the light to provide clarity to the atmosphere. God divides this primordial veil of water vapor above from the liquid water resting on earth’s surface with an expanse of firmament or vapor free sky. The waters on the earth are divided by the sky into two reservoirs of water; a canopy of water vapor or cloud above the earth and the liquid water lying on the earth.
The emphasis of these first two days is a description of the administrations of light in the earth. God first institutes periods of time called days for his expression of light in the earth. God then modifies the impact of the light by creating a vapor free expanse so that light could further illuminate the earth. This emphasis on the nature and function of light in creation reveals the shaping of the physical nature of the earth but also the further advancement of God’s fundamental nature as light in creation.