Why did the Biblical God "harden" the Heart of Pharaoh?

a reply to: Maximus2014

So God hardened Pharaoh's heart so that the Israelites could feel free to go on a massive plundering spree?

That's a possible but rather novel explanation.

I believe that if you read the full chapter starting at verse 1 instead of just pulling out verse 12, you see that Pharaoh had already hardened his heart against the Lord out of anger and jealousy. The Lord always works in the same fashion: call a messenger to tell the people of their disobedience (sin) and need for repentance, warn them of the consequences of not repenting, remind them of the eternal blessings of obedience, deliver the consequences for their actions. This is no different.

Christ, being one in purpose with his Father in Heaven, preached the same message with the additional explanation that through His atoning sacrifice all sins can be forgiven for those who are truly repentant and come to know Him as the Savior. This helps explain the perceived differences between the OT and NT impression of God. As man progressed on earth and became more distanced from God it was necessary to provide further doctrine and a physical Savior as was the plan from the beginning.