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. (10:21)

And Moses stretched forth his hand toward heaven; and there was a thick darkness in all the land of Egypt three days: (10:22)

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. (10:23)