"When we dream of first being filthy and then getting clean, when we do not know we are dreaming, both the filth and the cleanliness seem to truly exist. When we know we are dreaming, the filth is mere appearance and the cleanliness is mere appearance. In the true nature of the dream, there is neither filth nor cleanliness. That is easy to understand -- please don't forget it."
~ Khenpo Tsultrim Gyamtso Rinpoche
Sun of Wisdom, p. 112.