妙法蓮華經文句 1.75

1.75

本迹解者，聲聞內祕外現，何甞保證涅槃；天人皆大薩埵，豈復耽染生死？皆是迹引二邊，而本常中道也。

In terms of origin and traces: The śrāvakas internally conceal [their attainment] and externally manifest [as disciples]—how could they ever cling to realizing nirvāṇa? Devas and humans are all great mahāsattvas—how could they indulge in and be defiled by saṃsāra? All of these are traces guiding those on the two extremes, whereas their origin is eternally in the Middle Way.