>>2719246the thing is, the pharaoh's father already killed many firstborns, and drew first blood, and taught his son the new pharaoh many wicked things, but God is patient with the new pharaoh, and is willing to give him many chances.
It wasn't God that stiffened pharaohs heart, but pharaohs own desires, like serpents, aka the devil… and he was raised spoiled and hard to deal with, so God slowly showed him, the real stubborn ass, his hand in all things.