When there is no interaction with external dharmas, then there are no mental dharmas. When form leads to sensation, and sensation to perception and conception, then a chain of associations, or mental dharmas, takes off in the mind, and the external object is left behind. Once the mind moves, it will continue to roll along, powered by its own activity. If the mind does not move, then both the internal and external disappear. When the interaction between internal mental activities and external form ceases, wisdom appears. At that time there is neither a mind nor any dharma to be found.

If mind and dharma are no longer there, then what are they to begin with? They are none other than Buddha-nature.