'Hardness' in the Bible

In the hardening of dust into hardness, And clods cleave together?

Who is as the wise? and who knoweth the interpretation of a thing? The wisdom of man causeth his face to shine, and the hardness of his face is changed.

And having looked round upon them with anger, being grieved for the hardness of their heart, he saith to the man, 'Stretch forth thy hand;' and he stretched forth, and his hand was restored whole as the other;

but, according to thy hardness and impenitent heart, thou dost treasure up to thyself wrath, in a day of wrath and of the revelation of the righteous judgment of God,

For I do not wish you to be ignorant, brethren, of this secret -- that ye may not be wise in your own conceits -- that hardness in part to Israel hath happened till the fulness of the nations may come in;

being darkened in the understanding, being alienated from the life of God, because of the ignorance that is in them, because of the hardness of their heart,