When his people broke the deal and incurred divine wrath, Moses told G‑d, “Forgive them. And if You do not, erase me from Your book that You have written.”
Meaning: “I know You want to forgive them. You love them no matter what. You loved them before, when they had all but abandoned You in Egypt, and You love them now as well. It’s only this book that stands in the way. And if so, I want no part of such a book.”
It was then that G‑d wrote forgiveness into His book.
And so must we.
Likkutei Sichot, vol. 21, pp. 173–180; ibid., vol. 9, pp. 237–242.