四明十義書 1.82

1.82

具如《止觀》去於丈尺唯取於寸，乃是於事造中去其所造，取能造以為所觀之境，故云伐樹得根、灸病得穴。乃是去其千枝百脈，唯取一根一穴立所觀境，故云先重明境。故《扶宗》云：以一念識心為境也。

In full accordance with the Zhiguan's discarding the yard and foot to take only the inch, this means that within phenomenal creation, one discards what is created and takes what can create as the object of contemplation. Therefore it says, "felling a tree, one reaches the root; cauterizing a sickness, one finds the acupuncture point." It means setting aside the thousand branches and hundred conduits, taking only the single root and single point to establish the object of contemplation; hence it says "first re-clarifies the object." Therefore the Fuzong says: taking a single thought-moment of conscious mind as the object.