Exodus 9:13-14

Then the LORD said to Moses, “Rise up early in the morning and present yourself before Pharaoh and say to him, ‘Thus says the LORD, the God of the Hebrews, “Let my people go, that they may serve me. For this time I will send all my plagues on you yourself, and on your servants and your people, so that you may know that there is none like me in all the earth.