'Harden' in the Bible

Harden not your hearts, as in the provocation, in the day of temptation in the wilderness:

While it is said, To day if ye will hear his voice, harden not your hearts, as in the provocation.

Again, he limiteth a certain day, saying in David, To day, after so long a time; as it is said, To day if ye will hear his voice, harden not your hearts.