Exodus 11:9-10 New Living Translation (NLT)

9. Now the lord had told Moses earlier, “Pharaoh will not listen to you, but then I will do even more mighty miracles in the land of Egypt.”

10. Moses and Aaron performed these miracles in Pharaoh’s presence, but the lord hardened Pharaoh’s heart, and he wouldn’t let the Israelites leave the country.

Exodus 11