Mar 3:5 And he looked around at them with anger, grieved at their hardness of heart, and said to the man, Stretch out your hand.” He stretched it out, and his hand was restored.

Rom 11:25 Lest you be wise in your own sight, I do not want you to be unaware of this mystery, brothers: a partial hardening has come upon Israel, until the fullness of the Gentiles has come in.
Eph 4:18 They are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart.
Copyright information for ESV