Exodus 10:21 Then the LORD said to Moses, “Stretch out your hand toward heaven, that there may be darkness over the land of Egypt, a darkness to be felt.” So Moses stretched out his hand toward heaven, and there was pitch darkness in all the land of Egypt three days. They did not see one another, nor did anyone rise from his place for three days, but all the people of Israel had light where they lived. Then Pharaoh called Moses and said, “Go, serve the LORD; your little ones also may go with you; only let your flocks and your herds remain behind.” But Moses said, “You must also let us have sacrifices and burnt offerings, that we may sacrifice to the LORD our God. Our livestock also must go with us; not a hoof shall be left behind, for we must take of them to serve the LORD our God, and we do not know with what we must serve the LORD until we arrive there.” But the LORD hardened Pharaoh’s heart, and he would not let them go. Then Pharaoh said to him, “Get away from me; take care never to see my face again, for on the day you see my face you shall die.” Moses said, “As you say! I will not see your face again.”
Revelation 16:10-11 The fifth angel poured out his bowl on the throne of the beast, and its kingdom was plunged into darkness. People gnawed their tongues in anguish and cursed the God of heaven for their pain and sores. They did not repent of their deeds.
Proverbs 4:19 The way of the wicked is like deep darkness; they do not know over what they stumble.
Isaiah 8:21-22 They will pass through the land, greatly distressed and hungry. And when they are hungry, they will be enraged and will speak contemptuously against their king and their God, and turn their faces upward. And they will look to the earth, but behold, distress and darkness, the gloom of anguish. And they will be thrust into thick darkness.
2 Peter 2:17 For them the gloom of utter darkness has been reserved.
This was no normal darkness, it had a supernatural element to it that could be felt. Light is not only a physical property; it is an aspect of God’s character (God is light and in Him is no darkness at all, 1 John 1:5). In judgment, God can withdraw His presence so significantly that the void remaining is darkness which may even be felt. Seemingly, God did not even allow artificial light sources to work. The Egyptians attempted to use candles and lamps but were unable to produce light. This was dramatic show of greatness over the prominent Egyptian god Ra, thought to be the sun god. With this, Pharaoh made his last offer to Moses. All the children of Israel could go into the wilderness for three days of sacrifice unto the LORD God, but they must leave their livestock behind. Undoubtedly, Pharaoh felt God was a hard bargainer and made the best deal for Himself that He could. Pharaoh still saw things as someone who thought he could bargain with the Creator. This shows that he still didn’t really know who the LORD God was, because He still had not submitted to Him. In exasperation, Pharaoh ordered Moses out and told him to never come back. Moses assured Pharaoh, “You have spoken well. I will never see your face again” – but this was not good news for Pharaoh. (Guzik)
“Pharaoh was now beyond reason, and God did not reason with him.” (Morgan)
The Darkness. – As Pharaoh’s defiant spirit was not broken yet, a continuous darkness came over all the land of Egypt, with the exception of Goshen, without any previous announcement, and came in such force that the darkness could be felt. (Keil)
It is hard to imagine the darkness spoken of in this plague. The total absence of light. I have read where cave explorers have experienced this total absence of light and how it was very unnerving and caused them some fear and anxiousness. However, they went into the cave with this being a possibility. They knew if they did not have artificial light and a means of tracking their way back they would be in trouble. They go into the cave with this in mind.
The darkness which God brought upon Egypt was more than this type of natural darkness. It was a thick darkness that only God could create and control.
Hell is a place of total darkness, separation from God, and of torment. Not only is there torment of the complete darkness but a burning of which there is no likeness. The flame and its burning effects never cease. Eternal damnation. Eternal torment. Eternal anguish. Eternal separation from God. These are all given as warnings to mankind should they reject and deny their Creator. Denying these warnings or giving them no regard does not make them untrue. It just clouds the mind of the soul who wishes to fulfill the lusts of their fleshly desires without concern for eternity. People like to think that their death is the end of everything. They believe there is no God Creator or nothing eternal. Like Pharaoh, they harden their hearts to God’s Word and things of God. There is a day of judgment coming for all mankind. Eternal life – Heaven or eternal death and torment – Hell.