Exodus 23:21 in the King James Version
Beware of him, and obey his voice, provoke him not; for he will not pardon your transgressions: for my name is in him.
Context
20 “Behold, I send an angel before you, to keep you by the way, and to bring you into the place which I have prepared.
21 Pay attention to him, and listen to his voice. Don’t provoke him, for he will not pardon your disobedience, for my name is in him.
22 But if you indeed listen to his voice, and do all that I speak, then I will be an enemy to your enemies, and an adversary to your adversaries.