大般涅槃經義記 7.353

7.353

自下第三廣前略中舉淺類深，前舉生性類空無性，今舉世諦助以顯之，「如彼世諦實無其性，為生說有」。虛空如是，實無其性，為眾生故說有虛空。

Below is the third [part], extensively treating the citation of the shallow to illustrate the deep in the earlier summary. Earlier, the nature of sentient beings was cited to illustrate that space has no nature; now conventional truth is cited to assist in clarifying it: "Just as that conventional truth truly has no nature, yet for the sake of sentient beings it is said to exist." Space is like this: truly it has no nature, yet for the sake of sentient beings it is said that space exists.