Wipe the slate clean

Origin

Before paper was widely accessible and affordable, students, merchants, and accountants relied on personal slates—small, smooth slabs of stone—to jot down calculations, lessons, and temporary notes using chalk. When a new lesson began, an error was made, or accounts were settled, the slate was literally wiped clean with a cloth or sponge. This simple, everyday action completely erased all previous marks, providing a perfectly fresh, blank surface. It was a tangible way to remove all traces of the past and start anew, and this very literal act of clearing the writing surface beautifully evolved into a metaphor for letting go of past mistakes, debts, or arguments and beginning again with a completely unburdened, unblemished record.