John 12:40
He hath blinded their eyes, and hardened their heart; that they should not see with their eyes, nor understand with their heart, and be converted, and I should heal them.
Acts 19:9
But when divers were hardened, and believed not, but spake evil of that way before the multitude, he departed from them, and separated the disciples, disputing daily in the school of one Tyrannus.
Hebrews 3:13
But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.