John Gills Exposition of the Bible Commentary - Genesis 1:8
And God called the firmament heaven ,.... Including the starry and airy heavens: it has its name from its height in the Arabic language, it being above the earth, and reaching to the third heaven; though others take the word "shamaim" to be a compound of two words, "sham" and "maim", that is, there are waters, namely, in the clouds of heaven: and the evening; and the morning were the second day ; these together made up the space of twenty four hours, which was another natural day; the... read more
Matthew Henry's Complete Commentary - Genesis 1:6-8
We have here an account of the second day's work, the creation of the firmament, in which observe, 1. The command of God concerning it: Let there be a firmament, an expansion, so the Hebrew word signifies, like a sheet spread, or a curtain drawn out. This includes all that is visible above the earth, between it and the third heavens: the air, its higher, middle, and lower, regions?the celestial globe, and all the spheres and orbs of light above: it reaches as high as the place where the stars... read more