Exodus 10:3-10

So Moses and Aaron went in to Pharaoh and told him, “This is what the Lord, the God of the Hebrews, says: How long will you refuse to humble yourself before me? Let my people go, that they may worship me.  But if you refuse to let my people go, then tomorrow I will bring locusts  into your territory. They will cover the surface of the land so that no one will be able to see the land. They will eat the remainder left  to you that escaped the hail; they will eat every tree you have growing in the fields. They will fill your houses, all your officials’ houses, and the houses of all the Egyptians — something your fathers and grandfathers never saw since the time they occupied the land until today.” Then he turned and left Pharaoh’s presence. Pharaoh’s officials asked him, “How long must this man be a snare  to us? Let the men go, so that they may worship the Lord their God. Don’t you realize yet that Egypt is devastated? ” So Moses and Aaron were brought back to Pharaoh. “Go, worship the Lord your God,” Pharaoh said. “But exactly who will be going? ” Moses replied, “We will go with our young and with our old; we will go with our sons and with our daughters, with our flocks and with our herds because we must hold the Lord’s festival.”  He said to them, “The Lord would have to be with you if I would ever let you and your families go! Look out — you’re heading for trouble.