20 Then the Lord said to Moses, ‘Get up early in the morning. Meet Pharaoh when he goes out to the river. Then say to him, “The Lord says: You must let my people go. Let them go to worship me. 21 If you do not let my people go, I will send thousands of flies on you. I will send them on your servants and on your people. I will send them into your houses. The houses of the Egyptians will be full of flies. The flies will cover all the ground where people live.
22 But it will be different in the region of Goshen, where my people live. I will not send flies there. Then you will know that I, the Lord, am doing my work here in this land. 23 I will make a difference between my people and your people. This miracle will happen tomorrow.” ’
24 That is what the Lord did. Great numbers of flies came into Pharaoh's house and into his servants' houses. The flies went all over Egypt and they destroyed the whole land.
25 Then Pharaoh called Moses and Aaron to come to him. He said to them, ‘Go! You can offer sacrifices to your God here, in Egypt.’ 26 But Moses said, ‘It would not be right to do that. The Egyptians do not like our sacrifices of animals. If we offer these sacrifices to the Lord our God, the Egyptians will be angry with is. They will throw stones at us to kill us. 27 So, we must go on a journey for three days into the desert. We will offer sacrifices to the Lord our God there, as he has told us to do.’
28 So Pharaoh said, ‘I will let you go. You may go into the desert and offer sacrifices to the Lord your God there. But do not go very far away. And pray for me too.’
29 Then Moses said, ‘I will leave you now, and I will pray to the Lord. Tomorrow, all the flies will go away from you, your officers and your people. But be careful! Do not deceive us, as you did before. You must really let the people go away to offer sacrifices to the Lord.’
30 So Moses left Pharaoh and he prayed to the Lord. 31 The Lord did what Moses asked him. All the flies left Pharaoh, his officers and his people. Not one fly remained! 32 But again, Pharaoh's mind became hard. He refused to let the people go.