The Light - 24:35
God is the light of the heavens and the earth. The example of His light is like this: a cavity with a lamp in it. The lamp is in a glass vessel. And that glass vessel is like a pearly planet. Its fuel is from a luxuriant tree that produces olive oil, which is not connected to the west nor to the east. Its oil gives light almost without touching fire. It is light upon light. Allah brings to His light whoever He wills. This is how Allah gives such examples to the people. Allah knows everything.
Why heavens (plural expression) how many heavens?
Explained in Detail/41:11
"Then He turned to the smoking sky and said to it and to the earth, "Come (out of chaos) willingly or unwillingly". They said, "We have come willingly."
Explained in Detail/41:12
So He completed them in two days as seven heavens and revealed to each heaven its special laws. And We equipped the lowest heaven with lamps and a system of protection. This is the plan of the Supreme and All-Knowing.
The Cow/2:29
It is He who created for you everything on the earth. Then He turned to the heavens and organized them into seven heavens. He is All-Knowing.
The Night Journey/17:44
The seven heavens and all that is in them glorify Him. There is nothing that does not praise and glorify Him, but you do not understand their remembrance. He is Compassionate, Forgiving
The Believers/23:86
"Say, "Who is the Lord of the seven heavens and the Lord of the great government?"
Divorce/65:12
It is Allah Who created the seven heavens and as much of the earth. The commands flow between them. So that you may know that Allah is all-powerful and that Allah encompasses all things with knowledge.
The Kingdom/67:3
He has created the seven heavens in layers. You will not find any flaw in the creation of the Most Merciful. Direct your gaze and see if you can see any crack in it.
The News/78:12
And We established above you seven firm (heavens).