Exodus 10:22
“And Moses stretched forth his hand toward heaven; and there was a thick darkness in all the land of Egypt three days:”
But the Lord hardened Pharaoh’s heart, so that he would not let the children of Israel go.
And the Lord said unto Moses, Stretch out thine hand toward heaven, that there may be darkness over the land of Egypt, even darkness which may be felt.
And Moses stretched forth his hand toward heaven; and there was a thick darkness in all the land of Egypt three days:
They saw not one another, neither rose any from his place for three days: but all the children of Israel had light in their dwellings.
And Pharaoh called unto Moses, and said, Go ye, serve the Lord; only let your flocks and your herds be stayed: let your little ones also go with you.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“He sent darkness, and made it dark; and they rebelled not against his word.”
“And ye came near and stood under the mountain; and the mountain burned with fire unto the midst of heaven, with darkness, clouds, and thick darkness.”
“And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain,”
“And the people stood afar off, and Moses drew near unto the thick darkness where God was.”
“A day of darkness and of gloominess, a day of clouds and of thick darkness, as the morning spread upon the mountains: a great people and a strong; there hath not been ever the like, neither shall be any more after it, even to the years of many generations.”