Reference

Exodus 10:21-29

Lenses of the 9th plague.
1. Creation/de-creation. The plagues attack Egypt and it is as if God is dismantling His work of creation. The last act of creation was to create man, last plague was to be the death of many. Creation/nature was given to us as one of the great gifts of God and now it's as if nature is testifying against Egypt.
2. Cultural + Religions. Egyptians took the natural forces and tuned them into gods to worship. Their greatest god was Re (sun god and lord of creation). The God of the Hebrews can bring darkness and light while it seems Re is powerless. God destroyed all the idols to show He is the one true God.
3. Personal experiences. Every 3rd plague comes without warning. The darkness appeared to come suddenly and could be "felt". This could mean that you needed to feel your way to get around, or it could be a heavy sandstorm, or it was a supernatural darkness associated with God's judgement and an ominous warning.
4. Prophetic. Exodus and Revelation (8:6, 16:1-11) have similarities.
5. Metaphorical. Kingdoms of dark and light. We see the Hebrews didn’t experience this darkness. Jesus told His disciples He was leaving, and they were to be the light of the world (taking on the responsibility for Him). There is darkness around us, but the light will have the last word (resurrection is coming).