Musar zu Schemot 10:17

Pharaoh's repentance was of the category described by Jeremiah. He even said it openly when he exclaimed in 10,17: ויסר מעלי רק את המות הזה, "In order that He should remove from me only this death!" His servants who told him "dismiss these people and let them serve their G–d, for do you not know yet that Egypt will perish?" were not much better. This is why Moses said to Pharaoh in 9,30: "I know that neither you nor your servants have yet experienced true reverence for the Lord G–d." Moses merely intimated that he knew that the motivation of Pharaoh's professed remorse was not a true תשובה. G–d confirmed this in 10,3 when He said to Pharaoh (through Moses): "How long do you refuse to humble yourself before Me?"