When was the light created?

The Book of Genesis states that God created the light on the first day (Gen 1:3), while it states that the sun, moon and stars were created on the fourth day (Gen. 1:14-18).

What is the difference between the two matters? And was the light created on the first day or the fourth?

Answer:

God created light on the first day as the Bible indicated.

But, what light? It is the substance of light, the shining mass of fire from which God made the sun, the moon and the stars on the fourth day. On the fourth day also God established the astronomical laws and the permanent relation between these celestial bodies…

 

— H.H Pope Shenouda III