Exodus 5:1, 3

And afterward Moses and Aaron came and said to Pharaoh, “Thus says the LORD, the God of Israel, ‘Let My people go that they may celebrate a feast to Me in the wilderness.’ ”

Then they said, “The God of the Hebrews has met with us. Please, let us go a three days’ journey into the wilderness that we may sacrifice to the LORD our God, otherwise He will fall upon us with pestilence or with the sword.”