妙法蓮華經玄義 9.43

9.43

能、所為四句，門名能通，理是所通。自有能通麁，所通亦麁；能通妙，所通麁；能通麁，所通妙；能通妙，所通亦妙。

The facilitating and the facilitated form four propositions: the gates are called the facilitating passage, and the principle is that which is facilitated to pass through. There are cases where the facilitating is crude and the facilitated is also crude; the facilitating is subtle and the facilitated is crude; the facilitating is crude and the facilitated is subtle; and the facilitating is subtle and the facilitated is also subtle.