法界次第初門 3.55

3.55

十五、不可得空。不可得空者，一切法及因緣畢竟不可得，故名為不可得空。又解云：上以諸法空，空一切法皆不可得。若作可得，則為斷滅。若知是不可得亦不可得，則於不可得中心不沒故，名不可得空也。

Fifteenth: unapprehendable emptiness. Unapprehendable emptiness: all dharmas as well as causes and conditions are absolutely unapprehendable, therefore it is called unapprehendable emptiness. Another explanation states: above, through the emptiness of all dharmas, all dharmas are emptied and are unapprehendable; if treated as apprehendable, it would be annihilation. If one knows that this unapprehendability is also unapprehendable, the mind does not sink into unapprehendability; hence it is called unapprehendable emptiness.