Exodus 10:19-21

19The Lord responded by shifting the wind, and the strong west wind blew the locusts into the Red Sea. Not a single locust remained in all the land of Egypt.

20But the Lord hardened Pharaoh’s heart again, so he refused to let the people go.

21Then the Lord said to Moses, “Lift your hand toward heaven, and the land of Egypt will be covered with a darkness so thick you can feel it.”