Then the LORD said to Moses, "Pay close attention to this. I will make you seem like God to Pharaoh. Your brother, Aaron, will be your prophet; he will speak for you.
Tell Aaron everything I say to you and have him announce it to Pharaoh. He will demand that the people of Israel be allowed to leave Egypt.
But I will cause Pharaoh to be stubborn so I can multiply my miraculous signs and wonders in the land of Egypt.
Even then Pharaoh will refuse to listen to you. So I will crush Egypt with a series of disasters, after which I will lead the forces of Israel out with great acts of judgment.
When I show the Egyptians my power and force them to let the Israelites go, they will realize that I am the LORD."
So Moses and Aaron did just as the LORD had commanded them.