Hebrews 4:7

4:7 So God again ordains a certain day, “Today,” speaking through David after so long a time, as in the words quoted before, “O, that today you would listen as he speaks! Do not harden your hearts.”

Hebrews 6:18

6:18 so that we who have found refuge in him may find strong encouragement to hold fast to the hope set before us through two unchangeable things, since it is impossible for God to lie.

Hebrews 8:9

8:9 “It will not be like the covenant that I made with their fathers, on the day when I took them by the hand to lead them out of Egypt, because they did not continue in my covenant and I had no regard for them, says the Lord.