The Chinese Zen Master Huineng once said, “Bodhi really has no tree; nor is clear mirror the stand; nothing’s there initially; so where can the dust motes land?”

The mirror does not really exist.  Although the dust motes keep failing, there is nothing for them land on or cling to, and there is nothing to wipe clean.

If you have peace in your heart, you have no dust that needs to be wipe clean in you no matter how dusty outside of you is.