Mark 6:52
52 for they did not understand about the loaves, but their hearts were uhardened.
Mark 8:17
17 And Jesus, aware of this, said to them, “Why are you discussing the fact that you have no bread? jDo you not yet perceive or understand? Are your hearts khardened?
Ephesians 4:18
18 They are darkened in their understanding, qalienated from the life of God because of the rignorance that is in them, due to their shardness of heart.