Exodus 10:6

3 Then Moses and Aaron went in to Pharaoh, and said to him, This is what the Lord, the God of the Hebrews, says: How long will you be lifted up in your pride before me? let my people go so that they may give me worship.

4 For if you will not let my people go, tomorrow I will send locusts into your land:

5 And the face of the earth will be covered with them, so that you will not be able to see the earth: and they will be the destruction of everything which up to now has not been damaged, everything which was not crushed by the ice-storm, and every tree still living in your fields.

6 And your houses will be full of them, and the houses of your servants and of all the Egyptians; it will be worse than anything your fathers have seen or their fathers, from the day when they were living on the earth till this day. And so he went out from Pharaoh.

7 And Pharaoh's servants said to him, How long is this man to be the cause of evil to us? let the men go so that they may give worship to the Lord their God: are you not awake to Egypt's danger?

8 Then Moses and Aaron came in again before Pharaoh: and he said to them, Go and give worship to the Lord your God: but which of you are going?

9 And Moses said, We will go with our young and our old, with our sons and our daughters, with our flocks and our herds; for we are to keep a feast to the Lord.