Hebrews 3:15

As it has been said: “Today, if you hear His voice, do not harden your hearts, as you did in the rebellion.”

Note Psalms 95:7–8

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

while it is said, “Today if you will hear his voice, don’t harden your hearts, as in the rebellion.”

while it is said, To-day if ye shall hear his voice, Harden not your hearts, as in the provocation.