'Harden Your Hearts' in the Bible

Why then do you harden your hearts as the Egyptians and Pharaoh hardened their hearts? When He had severely dealt with them, did they not allow the people to go, and they departed?

Do not harden your hearts, as at Meribah,As in the day of Massah in the wilderness,

Do not harden your hearts as when they provoked Me,As in the day of trial in the wilderness,

while it is said,“Today if you hear His voice,Do not harden your hearts, as when they provoked Me.”

He again fixes a certain day, “Today,” saying through David after so long a time just as has been said before,“Today if you hear His voice,Do not harden your hearts.”