Genesis 1:7

And let it divide between water and water: and it was so. And God made the firmament; and God divided between the water which was under the firmament, and the water above the firmament: and it was so. As the excessive volume of water bore along over the face of the earth, the earth was by reason thereof "invisible" and "formless." When the Lord of all designed to make the invisible visible, He fixed then a third part of the waters in the midst; and another third part He set by itself on high, raising it together with the firmament by His own power; and the remaining third He left beneath, for the use and benefit of men. Now at this point we have an asterisk. The words are found in the Hebrew, but do not occur in the Septuagint.

Before laying hold of the meaning of Scripture let us try to meet objections from other quarters. We are asked how, if the firmament is a spherical body, as it appears to the eye, its convex circumference can contain the water which flows and circulates in higher regions? What shall we answer? One thing only: because the interior of a body presents a perfect concavity it does not necessarily follow that its exterior surface is spherical and smoothly rounded. Look at the stone vaults of baths, and the structure of buildings of cave form; the dome, which forms the interior, does not prevent the roof from having ordinarily a flat surface. Let these unfortunate men cease, then, from tormenting us and themselves about the impossibility of our retaining water in the higher regions. Now we must say something about the nature of the firmament, and why it received the order to hold the middle place between the waters. Scripture constantly makes use of the word firmament to express extraordinary strength. The Lord my firmament and refuge. I have strengthened the pillars of it. Praise him in the firmament of his power. The heathen writers thus call a strong body one which is compact and full, to distinguish it from the mathematical body. A mathematical body is a body which exists only in the three dimensions, breadth, depth, and height. A firm body, on the contrary, adds resistance to the dimensions. It is the custom of Scripture to call firmament all that is strong and unyielding. It even uses the word to denote the condensation of the air: He, it says, who strengthens the thunder. Scripture means by the strengthening of the thunder, the strength and resistance of the wind, which, enclosed in the hollows of the clouds, produces the noise of thunder when it breaks through with violence.

The waters were divided so that some were above the firmament and others below the firmament. Since we said that matter was called water, I believe that the firmament of heaven separated the corporeal matter of visible things from the incorporeal matter of invisible things.

Firmament: Not that in which the stars are set, but the part of the atmosphere where the clouds are collected, and which has received the name firmament from the firmness and density of the air.

And God made the firmament,....

You will find those words six times upon the first page of Scripture. God spoke and said, "Let there be a firmament." "And it was so." He said, "Let the dry land appear." "And it was so." He bade the earth bring forth grass, "And it was so." He ordained the sun and moon for lights in the firmament of Heaven. "And it was so." Whatever it was that He willed, He did but speak the Word, "and it was so." In no single case was there a failure. There was not even a hesitation, a pause or a demand for a more powerful agency than the Divine Word. In each case, Jehovah spoke, "and it was so." Nor is this first week of Creation the only instance of the kind, for in no case has the Word of God fallen to the ground—whether of promise or of threat—the Word has been confirmed and fulfilled. "As it was in the beginning, it is now, and ever shall be, world without end." Whatever the mighty God decrees, foretells, declares, or promises shall, before long come to pass. I shall ask you to accompany me in a mental voyage down the stream of history to show that this has been the case as far as all history is concerned up till now. ' 'And it was so." The Lord's will has been Law. His Word has been followed by fact. Dictum factum, as the Latins say. We shall then endeavor to show that with an Immutable God, it will be so continually in the great and in the small—in the affairs of the world—and in our own personal matters. What God has promised shall come to pass! And at the winding-up of all history, it shall be said, "God said this and that, and it was so." I. We stand at the fountainhead of human history and hear the Lord declare to our parents that in the day in which they should break His commands and eat of the forbidden fruit, they would surely die. "And it was so." They died that moment.