Like days two through six, day-four begins with Elohim continuing to speak (imperfect Hebrew verb). The day naturally divides into two parts: God’s continuing commands and the continuing results of those commands.
The commands, verse 14 - 15: And Elohim continues to say there shall becoming luminaries in the raqiya of the heavens be dividing between day and night. And they shall be for signs and for appointments (seasons) and for days and years. And let luminaries in the raqiya of the heavens be giving light on the Earth, and it was so.
Moses used raqiya five times on day two to refer to a spreading atmosphere that separated waters above and below. Day-four uses raqiya three times concerning the luminaries of the heavens. I render raqiya as “that which spreads out” or the “spreading place,” as I did for day two.
The results, verse 16 - 18: And Elohim continued to make (imperfect verb) two great luminaries, the greater luminary to rule the day and the lesser luminary to rule the night and the stars. He continued to be placing them in “the spreading place” (raqiya) to be lighting the earth and to be ruling over the day and be dividing the light from darkness, and it was so.
The end of the day, verse nineteen: And the evening and morning - day four.
What does Moses mean by greater and lesser luminaries? He adds the stars to the list so evidently they are the Sun, Moon and stars. The text mentions four times that the luminaries are to divide day and night, illuminate the Earth, shine on the Earth and divide light from darkness.
Moses used imperfect, continuing action, verbs for the commanding, making and placing of these luminaries. No completed action (perfect) verbs are found in the events of this day. There is no reference to creating the luminaries out of nothing, ex nihilo. Perhaps He continued to make them out of the unformed things He created first: the plural heavens and the earth. Remember, the Earth was formless until He continued to command light to continue to be. Perhaps the heavens also were originally formless and they also continued to receive form as God continues to command light to continue to be.
The continual commanding, forming and placing of the heavenly luminaries began on day four. We do not know (from this scripture) when or if the forming and placing of the luminaries stopped. Several other Scriptures, written after Moses, expound on the spreading heavens.
Zechariah 12:1 The Lord continues (in unbroken continuity) to stretch out the heavens and lay the foundation of the earth.
Isaiah 45:12 the Lord made the earth and the stretched out the heavens (perfect - completed action).
Isaiah 44:24 The Lord (in unbroken continuity) continues to stretch out the heavens and to spread out the earth. Why does one text use completed action verbs and another passage, by the same author, say He is continuing to do so?
Isaiah 51:13 The Lord continues (in unbroken continuity) to spread out the heavens and lay the foundations of the earth.
Isaiah 42:5 He continues (in unbroken continuity) to create the heavens and stretch them out.
Job 26:7 He continues to actively and in unbroken continuity stretch out the north over the empty place and hang the earth on nothing. The north is relatively empty because it is the opposite direction from the core of the Milky Way. If the stars continue to emerge from the core, they would spread out over the empty place to the north.
In Isaiah 40:26 we find completed action and continuing verbs in the same verse. He commands us to lift up our eyes and look - He created (completed action) the heavens. He continues in unbroken continuity to bring out their hosts, to cause them to exit. He continues to number them and call them by name, yet none go missing. How could He complete the creation of the heavens yet continue to bring their hosts out?
Taxpayers have funded huge telescopes that visualize the early universe in X-rays, visible, infrared and microwave. There are probably more than a trillion galaxies stretching out in all directions. The space between galaxy clusters is empty of obscuring gas. The speed of light is extremely slow relative to cosmic distances so that we see back to the creation era.
Isaiah 40:26 commands us to lift up our yes and look at what He created and how He continues to call the starry hosts to come out. Psalm 19 says the plural heavens are intensely and continually declaring his glory. The spreading place (raqiya) is causally, in unbroken continuity, showing the work of his hands.
I have combined two NASA images, one of the local galaxy M51 and in the lower right corner a primordial galaxy (UDF 3031) as it looked long ago. The Pinwheel covers an area of about 300,000 square seconds of our sky. Its arms are made of equally spaced clumps of stars imbedded in streams of dust with a sibling galaxy at the end of one arm. The light from M51 shines at about 99% of the frequencies emitted by modern atoms.
Hubble Ultra Deep 3031 covers about 5 square seconds of our sky so it is magnified 60,000 times compared to the Pinwheel. It has a bared center with two arms of distinct, equally-spaced, blue globs (like beads on a necklace) emerging from one end of the bar. It also has an orange sibling at the end of one arm. The arms have only rotated out about half a turn. The lumpy arms shine at higher frequencies than the core. UDF 3031 shines at about 42% of the frequencies emitted by modern atoms.
What we observe supports a literal rendering of day four. We do not see the unformed matter that He created on day one. However, we do occasionally observe bursts of intense gamma light arriving from that ancient universe. The burst appear to come from the areas where arms are forming in primordial spirals. Evidently this is the light that continues to give form to matter, from God’s continuing commands. We observe (at many ranges and all directions) how the stars continue to form and spread out in billions of spreading places (raqiya). Please notice that we do not see any evidence that the invisible vacuum of space-time is spreading out. Instead we observe the frequencies of atomic clocks, the space matter takes up and the inertial properties changing as stars continue to emerge and spread out. Billions of galaxies grew into huge growth spirals as the stars continued to form and spread out in countless spreading places. What we observe is the very things Moses recorded began on day four.
A Christian might refuse to look at the sky because it does not fit their vision of a young universe. Lift up you eyes and observe that the stars streams are accelerating outwards (the orbits not closing) along with the atomic clocks. Over the centuries, astronomers have measured a decreasing solar parallax, as though the solar system is also spreading out. Moses wrote that He continues to form the luminaries (Sun, Moon and stars) and continues to place them the spreading place, raqiya. Even the Sun and Moon continue to spread out. The literal account of day four does not support the western concept of an actual, linear time (24-hour fixed length days). No wonder ancient people grew skulls with thick brows. They lived for geological ages in few days, as Job explained in chapter 14. The days and years have been accelerating as the heavenly bodies continue to spread apart. Lift up your eyes and look, not at mathematical figures, but at the only history that is visible as it happened. I recommend that you go back and click on the picture for an expanded view of how galaxies have intrinsically grown. What is visible is powerful evidence for a literal rendering of the creation account.