妙法蓮華經玄義 8.151

8.151

此三十七品是行道法，將至涅槃城有三門，所謂苦下二行，為空解脫門。集道各四，苦下有二，是無作解脫門。滅下有四，是無相解脫門。若涅槃門開，即得入也。故佛於《須跋陀羅經》中，決定師子吼，唯我法中有八正道，外道法中，尚無一道，何況八道耶。

These thirty-seven factors are the dharmas for practicing the path, leading toward the city of nirvāṇa, which has three gates. That is, the two aspects under suffering form the gate of emptiness liberation. The four each under origin and path, along with the two under suffering, are the gate of wishlessness liberation. The four under cessation are the gate of signlessness liberation. If the gate of nirvāṇa opens, one can immediately enter. Therefore, in the Subhadra-sūtra the Buddha made the definitive lion's roar: 'Only in my Dharma is there the eightfold noble path; in non-Buddhist dharmas, there is not even a single path, much less the eightfold path!'