The Bible does not address this question. The Bible says simply that was the way of it. For centuries, students of the Bible have puzzled over this. Part of the answer might have to do with Pharaoh’s unique role in Egypt. He was considered to be the physical manifestation of the most powerful Egyptian god. In all likelihood, Pharaoh enjoyed a supremely privileged upbringing. Anything he wanted was his by royal command. Pharaoh ate the choicest foods, wore the finest clothes, and enjoyed the most thorough education. He had the best of everything. Add a little more speculation to the picture. Suppose, too, that Pharaoh was never taught (or never accepted) lessons in humility, gratitude, and compassion. Instead, he cultivated a personality of pride, selfishness, and tyranny.

Throughout the first few confrontations between Moses and Pharaoh, God gave Pharaoh several chances to change his mind and repent. Pharaoh didn’t, though. That was his choice. Still, God knew Pharaoh’s heart, just like he knew Moses’. So during the last five plagues, perhaps God simply expedited what was bound to be Pharaoh’s reaction anyway.