Genesis 1:14-15  "And God said, "Let" (there's that word 'let' again; remember, the word means to allow a process to occur.  It is not creative) there be lights in the firmament of the heaven to divide the day from the night; and "let" them be for signs and for seasons, and for days, and years; And "let" them be for lights in the firmament of the heaven to give light upon the earth: and it was so."

There are three more verses on this subject of 'lights'. (vs. 16-18) This is the longest passage on any subject so far. Lights in the firmament.  The heavenly expanse.

I've always wondered why this was so important to God that he gave five verses on this subject and nothing on dinosaurs.  Or on the life forms in the water, or on what happened in the verses between vs. 1 and vs. 2.  But He didn't.

We are getting ready for man to appear in this story.  The lights in the firmament will speak to man concerning God.  Concerning creation, and Creator.

Psalms 19:1-3,  "The heavens declare the glory of God; and the firmament shows his handwork.  Day unto day they utter speech, and night unto night they show knowledge.  There is no speech, nor language, where their voice is not heard."

Jesus said, "I am the light of the world..."

Also, "Let your light shine before men..."

Also, "Don't put your light under a basket..."