Exodus 5:1-2

After that Moses and Aaron approached Pharaoh. They said, “GOD, the God of Israel, says, ‘Free my people so that they can hold a festival for me in the wilderness.’” Pharaoh said, “And who is GOD that I should listen to him and send Israel off? I know nothing of this so-called ‘GOD’ and I’m certainly not going to send Israel off.”