四明十義書 1.197

1.197

良由灸病得穴，故百病自差。伐樹得根，故千枝自枯。故云任運攝得權實所現，以皆由理具方有事用故。只觀理具三千俱空假中，故事用所造自然皆空假中，故云任運攝得權實所現。豈須千枝遍斬、六分全燒方名伐樹灸病耶？

This is precisely because when moxibustion hits the right acupoint, the hundred diseases are cured of themselves; when felling a tree one strikes the root, the thousand branches wither of themselves. Therefore it is said that [this contemplation] naturally embraces all that is manifested by the provisional and the real, because it is entirely due to inherent principle that phenomenal functions exist. By only contemplating the three thousand [dharmas] inherently possessed in principle as all empty, provisional, and middle, the phenomenal functions that are produced naturally become all empty, provisional, and middle; hence it is said that it naturally embraces all that is manifested by the provisional and the real. How could one need to sever all thousand branches one by one, or burn all six parts of the body, before it can be called felling a tree or applying moxibustion to an ailment?