Exodus 10:21-23
Darkness over the Land
21 Then the Lord said to Moses, “(A)Stretch out your hand toward the sky, that there may be darkness over the land of Egypt, even a darkness (B)which may be felt.”
22 So Moses stretched out his hand toward the sky, and there was (C)thick darkness in all the land of Egypt for three days.
23 They did not see one another, nor did anyone rise from his place for three days, (D)but all the sons of Israel had light in their dwellings.