WHATTTTTT?
Exodus 4:21 And the LORD said unto Moses, "when thou goest to return into Egypt, see that thou do all those wonders before Pharaoh, which I have put in thine hand: BUT I will harden his heart, that he shall not let the People go.
Pharaoh's heart was hardened before Moses ever spoke to him.
HELLO.
Did you read it? This was before the last of the plagues. Hardening the heart means turning off God's council to the man- his conscience. This is an ongoing thing in the exchange that happens as a matter of course. The verse you cite is NOT before moses ever spoke to him and is apparent in the passage plainly. It ocurrs when - BEFORE THE LAST CURSE on the land. You seem to have a knack for lying about what the scripture says. You also fail to point out that while turning the volume down on his conscience, he provided Moses with proofs to present to the Pharaoh so that Pharaoh could believe and consent. Of Pharaoh's own will he resisted to the end. Conscience and will are not the same thing.