Genesis 1:6 - Coke's Commentary on the Holy Bible

Let there be a firmament in the midst of the waters— After having given an account of the generation of light, the sacred writer goes on to inform us of the generation of the air, or of that expansive element which fills the space between the earth and the highest regions, and which goes under the general name of the heavens. This air, in its first created state, was intermixed with the other elements in the chaotic mass; upon which a motion having been impressed by the divine energy, and the light having emerged, the Almighty next directs the air, according to its nature, to operate amidst the waters; and by its expansive and compressing power, to carry some of these waters aloft with it, and to keep the rest in their due station below on the earth. This I take to be the meaning of the present verse; to which not only the words, but the nature of things, correspond. For rekiang (רקיע), as our translators observe in the margin, (though, after the Vulgate and LXX, they have rendered it firmament,) signifies expansion; or rather the air or heaven in a state of expansion; for expansion necessarily implies an agent to expand, and here an agent is expressed, which was to divide or separate the waters; which agent is called, Genesis 1:8 heaven. As the light, which makes the day, is called day; and the darkness, night: so, that which makes the heaven, i.e.. the air, is called heaven. Those who understand the properties of the air, which is peculiarly elastic, and therefore expansive and compressing, will see the great propriety of the original, rechio, which is derived from the verb recho, to stretch forth, extend, distend, expand every way. And nothing but our being accustomed immediately to annex the idea of the regions of supernal bliss to the word heaven, when we hear or read it, could make it appear strange to us, that this agent is called heaven or heavens; since the whole space we see, and commonly call heaven, is nothing more than the air. How far this air or heaven may rise and extend, I cannot determine. But it seems to me most probable (and I have Sir Isaac Newton's authority, or at least supposition on my side) that the whole planetary space is filled with a fine and subtle ether; which, it is probable, grows finer and finer as it approaches the central fire, the sun, and becomes grosser, and grosser the nearer it approaches the center of our planet. By the firmament, therefore, I would understand all that immense space which every way surrounds our earth, and extends to the limits of our system, and which I conceive to be filled with ether, denser or finer, in proportion to its proximity to, or distance from, the sun.