Matthew 19:8 - He saith unto them, Moses because of the hardness G4641 of your hearts G4641 suffered you to put away your wives: but from the beginning it was not so.
Mark 10:5 - And Jesus answered and said unto them, For the hardness G4641 of your heart G4641 he wrote you this precept.
Mark 16:14 - Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, G4641 because they believed not them which had seen him after he was risen.