'Hardness' in the Bible

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;