Genesis 1:14

(14) Let there be lights (luminaries) in the firmament (or expanse) of the heaven.—In Hebrew the word for light is ôr, and for luminary, ma-ôr, a light-bearer. The light was created on the first day, and its concentration into great centres must at once have commenced; but the great luminaries did not appear in the open sky until the fourth day. With this begins the second triad of the creative days. Up to this time there had been arrangement chiefly; heat and water had had their periods of excessive activity, but with the introduction of vegetation there came also the promise of things higher and nobler than mechanical laws. Now, this fourth day seems to mark two things: first, the surface of the earth has become so cool as to need heat given it from without and secondly, there was now a long pause in creation. No new law in it is promulgated, no new factor introduced; only the atmosphere grows clearer, the earth more dry; vegetation does its part in absorbing gases; and day by day the sun shines with more unclouded brilliancy, followed by the mild radiance of the moon, and finally, by the faint gleamings of the stars. But besides this, as the condensation of luminous matter into the sun was the last act in the shaping of our solar system, it is quite possible that during this long fourth day the sun finally assumed as nearly as possible its present dimensions and form. No doubt it is still changing and slowly drawing nearer to that period when, God’s seventh day of rest being over, the knell of this our creation will sound, and the sun, with its attendant planets, and among them our earth, become what God shall then will. But during this seventh day, in which we are now living, God works only in maintaining laws already given, and no outburst either of creative or of destructive energy can take place.

Let them be for signs—i.e., marks, means of knowing. This may be taken as qualifying what follows, and would then mean, Let them be means for distinguishing seasons, days, and years; but more probably it refers to the signs of the zodiac, which anciently played so important a part, not merely in astronomy, but in matters of daily life.

Seasons.—Not spring, summer, and the like, but regularly recurring periods, like the three great festivals of the Jews. In old time men depended, both in agriculture, navigation, and daily life, upon their own observation of the setting and rising of the constellations. This work is now done for us by others, and put into a convenient form in almanacks; but equally now as of old, days, years, and seasons depend upon the motion of the heavenly orbs.