wipe (one's) slate clean
To erase the record of one's wrong-doings, likened to wiping the contents off of a piece of slate, formerly used as a reusable writing surface. I had been late a bunch of times, but after he heard that I'd been struggling so much at home, my boss said he would wipe my slate clean. Mom said she would wipe your slate clean if you pay for the vase you broke.