1:3-5 God said, Let there be light; he willed it, and at once there was light. Oh, the power of the word of God! And in the new creation, the first thing that is wrought in the soul is light: the blessed Spirit works upon the will and affections by enlightening the understanding. Those who by sin were darkness, by grace become light in the Lord. Darkness would have been always upon fallen man, if the Son of God had not come and given us understanding, 1Jo 5:20. The light which God willed, he approved of. God divided the light from the darkness; for what fellowship has light with darkness? In heaven there is perfect light, and no darkness at all; in hell, utter darkness, and no gleam of light. The day and the night are the Lord's; let us use both to his honour, by working for him every day, and resting in him every night, meditating in his law both day and night.

Ge 1:3-5. The First Day.

3. God said—This phrase, which occurs so repeatedly in the account means: willed, decreed, appointed; and the determining will of God was followed in every instance by an immediate result. Whether the sun was created at the same time with, or long before, the earth, the dense accumulation of fogs and vapors which enveloped the chaos had covered the globe with a settled gloom. But by the command of God, light was rendered visible; the thick murky clouds were dispersed, broken, or rarefied, and light diffused over the expanse of waters. The effect is described in the name "day," which in Hebrew signifies "warmth," "heat"; while the name "night" signifies a "rolling up," as night wraps all things in a shady mantle.