Exodus 5:1-3

Afterwards Moses and Aaron went to Pharaoh and said, ‘This is what the LORD, the God of Israel, says: “Let my people go, so that they may hold a festival to me in the wilderness.” ’ Pharaoh said, ‘Who is the LORD, that I should obey him and let Israel go? I do not know the LORD and I will not let Israel go.’ Then they said, ‘The God of the Hebrews has met with us. Now let us take a three-day journey into the wilderness to offer sacrifices to the LORD our God, or he may strike us with plagues or with the sword.’