Moses and Aaron appear before Pharaoh and ask him to let them go into the wilderness and sacrifice to the LORD God. Pharaoh does not let them go but rather increases their work load. The Hebrews are mad at Moses, the Egyptians are mad at Moses, he cries out to God that they are worse off than before; and he has no idea, God is just getting warmed up.

Exodus 5

Afterward Moses and Aaron went in and told Pharaoh “This is what the LORD God of Israel says: ‘Let my people go, that they may hold a feast to me in the wilderness.’”