Verses with the word hardeneth in the Old Testament (3 verses):
Proverbs 21:29
A wicked man hardeneth his face: but as for the upright, he directeth his way.
Proverbs 28:14
Happy is the man that feareth alway: but he that hardeneth his heart shall fall into mischief.
Proverbs 29:1
He, that being often reproved hardeneth his neck, shall suddenly be destroyed, and that without remedy.