Exodus 10:20-24

But the Lord hardened Pharaoh’s heart, and he did not let the sons of Israel go. Darkness over the Land

Then the Lord said to Moses, “Reach out with your hand toward the sky, so that there may be darkness over the land of Egypt, even a darkness which may be felt.”

So Moses reached out with his hand toward the sky, and there was thick darkness in all the land of Egypt for three days.

They did not see one another, nor did anyone rise from his place for three days, but all the sons of Israel had light in their dwellings.

Then Pharaoh called for Moses, and said, “Go, serve the Lord; only let your flocks and your herds be left behind. Even your little ones may go with you.”