In the story of the woman caught in adultery, perhaps the mark Jesus draws in the sand is the same mark God draws on Cain. Perhaps the miracle here is that the men in that story walk away because they suddenly don't remember the woman's sin.
Perhaps it's a story of a fresh start.
I, even I, am he who blots out
your transgressions, for my own sake,
and remembers your sins no more.
Genesis 43:25 (NIV)