妙法蓮華經玄義 2.13

2.13

若十數依法界者，能依從所依，即入空界也。十界界隔者，即假界也。十數皆法界者，即中界也。欲令易解，如此分別。得意為言，空即假、中，無一二三，如前（云云）。

If the ten numbers depend on the dharma realm, the dependent follows the locus of dependence, which enters the realm of emptiness. That the ten realms have separate boundaries is the provisional realm. That the ten numbers are all the dharma realm is the middle realm. Desiring to make it easy to understand, one makes such distinctions. But stating it according to the grasped meaning, emptiness is identical with the provisional and the middle, without one, two, or three, as explained above.