'Harden Your Hearts' in the Bible

harden your hearts, - as in the embitterment, in the day of testing in the desert,

So long as it is said - To-day, if, unto his voice, ye would hearken, do not harden your hearts, - as in the embitterment.

Again, he marketh out a certain day, To-day, in David, saying - after so long a time as this, - according as it hath been said before: - To-day, if, unto his voice, ye would hearken, do not harden your hearts.