NET
21 The Lord said to Moses, “Extend your hand toward heaven so that there may be darkness over the land of Egypt, a darkness so thick it can be felt.”
Darby
21 And Jehovah said to Moses, Stretch out thy hand toward the heavens, that there may be darkness in the land of Egypt so that one may feel darkness.
KJV
21 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.