“Go, tell Pharaoh king of Egypt that he must release ¹  the Israelites from his land.”

Then the Lord said to Moses, “Now you will see what I will do to Pharaoh, ¹  for compelled by my strong hand ²  he will release them, and by my strong hand he will drive them out of his land.” ³ 

You are to speak ¹  everything I command you, ²  and your brother Aaron is to tell Pharaoh that he must release ³  the Israelites from his land.

So Moses and Aaron did all these wonders before Pharaoh, but the Lord hardened Pharaoh’s heart, and he did not release the Israelites from his land.