Exodus 9:1

Then the LORD said to Moses, “Go to Pharaoh and tell him that this is what the LORD, the God of the Hebrews, says: ‘Let My people go, so that they may worship Me.

Then the LORD said unto Moses, Go in unto Pharaoh, and tell him, Thus saith the LORD God of the Hebrews, Let my people go, that they may serve me.