Verses 3-4:
And God said, Let there be light: and there was light.
And God saw the light, that it was good: and God divided the light from the darkness.
Comments:
Light seems to me like the next reasonable, logical step in the formation of the world. First, to have the light shine upon the world, and second, to regulate how much time any given part of the world spends in light or in darkness - to set the hours of the day in the rotation of the earth, for there to be enough light for the living things that are to be put upon the earth, but not too much - or some other formative step in ordering or organizing things that can be construed as dividing the light from the darkness and creating cycles of day and night on the earth.
Light is necessary for all living things on this world; even ones that can survive in complete darkness still at some point rely upon complex ecosystems that would not be able to maintain themselves without light on some of the living organisms (both flora and fauna) that are a part of them.
This fact makes light very powerful as a symbol, and both light and sources of light are significant in scripture, with great meaning whether the light referred to is literal or symbolic. (we can also see in the scriptures that water, as another thing necessary for life, is symbolically important and meaningful when referred to in scripture, whether it is literal or symbolic water)
One other thing interesting to me, is that in these verses it does not explicitly say that God created the light at that time - by God’s word it was commanded to be upon the earth, God brought it and divided it from the darkness, arranged for the world to have the light that it would need, but the words “created” and “made” are not used in reference to the light at this time. Which does not necessarily mean that God did not ever create the light.
Perhaps, in the beginning of everything (and not just the beginning of this world and everything on it) God did create the light (the existence of light, not just sources of light) and thus came before it even if in a sense they are both eternal and have always existed, always were. I believe that as far as we could measure or comprehend in a finite mortal existence in three dimensions, God and light are both eternal, that light existed before this particular universe existed, just as the laws of nature, of physics and mathematics existed. (though not constrained by our current limited understanding and limited ability to create notations and languages to describe them)
Thus, in the earth’s creation, I feel it more a matter of bringing light to the earth, rather than the very concept and essence of light being created at that time.