“You do not wash the cup, you wash the dirt; if you were to wash the cup, it would disappear completely. So, it is the dirt that is washable and has nothing at all to do with the cup.
This example is quite a good illustration of one of the most profound theories of the bodhisattvayana: we all have the potential to become Buddhas because we have Buddha nature. The problem is we have yet to realise it.”
– Dzongsar Khyentse Rinpoche
from the book “Not for Happiness: A Guide to the So-Called Preliminary Practices”