'Hardens' in the Bible

“My flesh is clothed with worms and a crust of dirt,My skin hardens and runs.

when the dust hardens like cast metaland the clods of dirt stick together?

A wicked man hardens his face; but as for the upright, he establishes his ways.

Happy is the one who is always reverent,but one who hardens his heart falls into trouble.

A man who hardens his neck after much reproofWill suddenly be broken beyond remedy.

So then, He shows mercy to those He wants to, and He hardens those He wants to harden.

But if any one has this world's wealth and sees that his brother man is in need, and yet hardens his heart against him--how can such a one continue to love God?