Exodus 23:21
Beware of him, and obey his voice, provoke him not; for he will not pardon your transgressions: for my name is in him.
Exodus 34:9
And he said, If now I have found grace in thy sight, O LORD, let my LORD, I pray thee, go among us; for it is a stiffnecked people; and pardon our iniquity and our sin, and take us for thine inheritance.