Exodus 10:19-21

Young's Literal Translation

¹⁹ and Jehovah turneth a very strong sea wind, and it lifteth up the locust, and bloweth it into the Red Sea -- there hath not been left one locust in all the border of Egypt;

²⁰ and Jehovah strengtheneth the heart of Pharaoh, and he hath not sent the sons of Israel away.

²¹ And Jehovah saith unto Moses, `Stretch out thy hand towards the heavens, and there is darkness over the land of Egypt, and the darkness is felt.'