Exodus 8:27-32

27 We must take a three-day trip into the wilderness to offer sacrifices to the LORD our God, just as he has commanded us.”
28 “All right, go ahead,” Pharaoh replied. “I will let you go into the wilderness to offer sacrifices to the LORD your God. But don’t go too far away. Now hurry and pray for me.”
29 Moses answered, “As soon as I leave you, I will pray to the LORD, and tomorrow the swarms of flies will disappear from you and your officials and all your people. But I am warning you, Pharaoh, don’t lie to us again and refuse to let the people go to sacrifice to the LORD .”
30 So Moses left Pharaoh’s palace and pleaded with the LORD to remove all the flies.
31 And the LORD did as Moses asked and caused the swarms of flies to disappear from Pharaoh, his officials, and his people. Not a single fly remained.
32 But Pharaoh again became stubborn and refused to let the people go.
Holy Bible. New Living Translation copyright© 1996, 2004, 2007, 2013 by Tyndale House Foundation. Used by permission of Tyndale House Publishers Inc., Carol Stream, Illinois 60188. All rights reserved.