19 I will make a distinction between my people and your people. This sign will take place tomorrow.
20 This the Lord did. Thick swarms of flies entered the house of Pharaoh and the houses of his servants; throughout Egypt the land was devastated on account of the swarms of flies.
21 Then Pharaoh summoned Moses and Aaron and said, “Go sacrifice to your God within the land.”
22 But Moses replied, “It is not right to do so, for what we sacrifice to the Lord, our God, is abhorrent to the Egyptians. If we sacrifice what is abhorrent to the Egyptians before their very eyes, will they not stone us?
23 We must go a three days’ journey in the wilderness and sacrifice to the Lord, our God, as he commands us.”
24 Pharaoh said, “I will let you go to sacrifice to the Lord, your God, in the wilderness, provided that you do not go too far away. Pray for me.”
25 Moses answered, “As soon as I leave you I will pray to the Lord that the swarms of flies may depart tomorrow from Pharaoh, his servants, and his people. Pharaoh, however, must not act deceitfully again and refuse to let the people go to sacrifice to the Lord.”