Exodus 3:19

17I have said, I will bring you up out of the affliction of Egypt to the land of the Canaanite, the Hittite, the Amorite, the Perizzite, the Hivite, and the Jebusite, to a land flowing with milk and honey.”’

18They will listen to your voice. You shall come, you and the elders of Israel, to the king of Egypt, and you shall tell him, ‘The LORD, the God of the Hebrews, has met with us. Now please let us go three days’ journey into the wilderness, that we may sacrifice to the LORD, our God.’

19I know that the king of Egypt won’t give you permission to go, no, not by a mighty hand.

20I will reach out my hand and strike Egypt with all my wonders which I will do among them, and after that he will let you go.

21I will give this people favor in the sight of the Egyptians, and it will happen that when you go, you shall not go empty-handed.