Exodus 10:21-23

21Then the Lord said to Moses, “1Stretch out your hand toward the sky, that there may be darkness over the land of Egypt, even a darkness 2which may be felt.”

22So Moses stretched out his hand toward the sky, and there was 3thick darkness in all the land of Egypt for three days.

23They did not see one another, nor did anyone rise from his place for three days, 4but all the sons of Israel had light in their dwellings.