法華文句記 7.137

7.137

約人故豎，約法故橫。又人法各有橫之與豎，具如前說，不可定判，故更以橫對實亦名為豎。

In terms of persons, it is vertical; in terms of dharmas, it is horizontal. Furthermore, persons and dharmas each have both horizontal and vertical aspects, fully as expounded before, and cannot be definitively determined; hence, when horizontal is contrasted with the real, it is also termed vertical.