Mark 6:52 - For they considered not the miracle of the loaves: for their heart was hardened. G4456
Mark 8:17 - And when Jesus knew it, he saith unto them, Why reason ye, because ye have no bread? perceive ye not yet, neither understand? have ye your heart yet hardened? G4456
John 12:40 - He hath blinded their eyes, and hardened G4456 their heart; that they should not see with their eyes, nor understand with their heart, and be converted, and I should heal them.
Romans 11:7 - What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded G4456
2 Corinthians 3:14 - But their minds were blinded: G4456 for until this day remaineth the same vail untaken away in the reading of the old testament; which vail is done away in Christ.