Exodus

²⁷We will go three days' journey into the wilderness, and sacrifice to the Lord our God, as he shall command us. ²⁸And Pharaoh said, I will let you go, that ye may sacrifice to the Lord your God in the wilderness; only ye shall not go very far away: entreat for me. ²⁹And Moses said, Behold, I go out from thee, and I will entreat the Lord that the swarms of flies may depart from Pharaoh, from his servants, and from his people, tomorrow: only let not Pharaoh deal deceitfully any more in not letting the people go to sacrifice to the Lord. ³⁰And Moses went out from Pharaoh, and entreated the Lord. ³¹And the Lord did according to the word of Moses; and he removed the swarms of flies from Pharaoh, from his servants, and from his people; there remained not one. ³²And Pharaoh hardened his heart this time also, and he did not let the people go.