Exodus 10:21

17Now therefore please forgive my sin again, and pray to the LORD your God, that he may also take away from me this death.”

18Moses went out from Pharaoh, and prayed to the LORD.

19The LORD sent an exceedingly strong west wind, which took up the locusts, and drove them into the Red Sea. There remained not one locust in all the borders of Egypt.

20But the LORD hardened Pharaoh’s heart, and he didn’t let the children of Israel go.

21The LORD said to Moses, “Stretch out your hand toward the sky, that there may be darkness over the land of Egypt, even darkness which may be felt.”

22Moses stretched out his hand toward the sky, and there was a thick darkness in all the land of Egypt for three days.

23They didn’t see one another, and nobody rose from his place for three days; but all the children of Israel had light in their dwellings.

24Pharaoh called to Moses, and said, “Go, serve the LORD. Only let your flocks and your herds stay behind. Let your little ones also go with you.”

25Moses said, “You must also give into our hand sacrifices and burnt offerings, that we may sacrifice to the LORD our God.