How exactly does God harden hearts & why does He do that?

Allyanna Walton: Please give detailed examples and/or illustrations. I’d like to understand

Donna Bedwell
He did, I believe, harden Pharoh’s heart… what God does is meant to bring glory to himself and enable his people to be glorified likewise. His ways are not ours.

Bob Dunn
People harden there hearts not God.

Serge Perez
This is a common misconception. Scripture is talking about the result, not the actions taken by God.
For example, in Exodus 7:3 – God is speaking of the result of him multiplying his signs and wonders. He is foretelling what He alone knows for certain, that despite the evidence/signs Pharaoh would continue to try and disprove or deny the power and providence of God over His people, even the world – hardening his heart of his own volition.
That said, God doesn’t harden his heart, Pharaoh’s heart was pre-destined to be hardened and God is simply declaring the truth to His people through their prophet so that they could receive also these signs and miracles as evidence of the power and providence of God over them. His true intent, isn’t to harden a man’s heart – but to protect and FREE His people.
It is much the same even now, for those with hardened hearts refuse, to acknowledge the love of the Father, even having seen and heard the truth many times in their lives themselves – but they are not prevented from acknowledging Him by anyone except themselves.