'Hardening' in the Bible

After looking around at them with anger, grieved at the hardness and arrogance of their hearts, He told the man, “Hold out your hand.” And he held it out, and his hand was [completely] restored.

I do not want you, believers, to be unaware of this mystery [God’s previously hidden plan]—so that you will not be wise in your own opinion—that a partial hardening has [temporarily] happened to Israel [to last] until the full number of the Gentiles has come in;