20 Then the Lord said to Moses, Rise up early in the morning and stand before Pharaoh as he comes forth to the water; and say to him, Thus says the Lord, Let My people go, that they may serve Me. 21 Else, if you will not let My people go, behold, I will send swarms [of bloodsucking gadflies] upon you, your servants, and your people, and into your houses; and the houses of the Egyptians shall be full of swarms [of bloodsucking gadflies], and also the ground on which they stand. 22 But on that day I will sever and set apart the land of Goshen in which My people dwell, that no swarms [of gadflies] shall be there, so that you may know that I am the Lord in the midst of the earth. 23 And I will put a division and a sign of deliverance between My people and your people. By tomorrow shall this sign be in evidence. 24 And the Lord did so; and there came heavy and oppressive swarms [of bloodsucking gadflies] into the house of Pharaoh and his servants' houses; and in all of Egypt the land was corrupted and ruined by reason of the great invasion [of gadflies].
25 And Pharaoh called for Moses and Aaron, and said, Go, sacrifice to your God [here] in the land [of Egypt]. 26 And Moses said, It is not suitable or right to do that; for the animals the Egyptians hold sacred and will not permit to be slain are those which we are accustomed to sacrifice to the Lord our God; if we did this before the eyes of the Egyptians, would they not stone us? 27 We will go a three days' journey into the wilderness and sacrifice to the Lord our God, as He will command us. 28 So Pharaoh said, I will let you go, that you may sacrifice to the Lord your God in the wilderness; only you shall not go very far away. Entreat [your God] for me. 29 Moses said, I go out from you, and I will entreat the Lord that the swarms [of bloodsucking gadflies] may depart from Pharaoh, his servants, and his people tomorrow; only let not Pharaoh deal deceitfully any more in not letting the people go to sacrifice to the Lord. 30 So Moses went out from Pharaoh and entreated the Lord. 31 And the Lord did as Moses had spoken: He removed the swarms [of attacking gadflies] from Pharaoh, from his servants, and his people; there remained not one. 32 But Pharaoh hardened his heart and made it stubborn this time also, nor would he let the people go.