Exodus 7:1-6 NIV
Then the LORD said to Moses, “See, I have made you like God to Pharaoh, and your brother Aaron will be your prophet. You are to say everything I command you, and your brother Aaron is to tell Pharaoh to let the Israelites go out of his country. But I will harden Pharaoh’s heart, and though I multiply my signs and wonders in Egypt, he will not listen to you. Then I will lay my hand on Egypt and with mighty acts of judgment I will bring out my divisions, my people the Israelites. And the Egyptians will know that I am the LORD when I stretch out my hand against Egypt and bring the Israelites out of it.”
Moses and Aaron did just as the LORD commanded them.
NIV: New International Version