大般涅槃經義記 6.421

6.421

第二喻中，將「生」喻聞，「不生」喻於不聞之義，「生已不生」類顯後句，如彼生相生諸法時不得說言生於不生，所況如是，已得聞時不得宣說聞於不聞，「不生不生」類向前句，如彼虛空不可生故正名不生不得言生，所況即是，不可聞法正名不聞不得言聞。

In the second analogy, "arising" is used to analogize hearing, and "non-arising" to analogize the meaning of not hearing; "having arisen, it does not arise" analogizes and reveals the latter phrase: just as when that mark of arising brings forth dharmas it cannot be said to arise from non-arising, the case illustrated is like this: having already attained hearing, one cannot declare that one hears what is not heard; "non-arising does not arise" analogizes the preceding phrase: just as space, because it cannot arise, is properly named non-arising and cannot be said to arise, the case illustrated is just this: a dharma that cannot be heard is properly named not hearing and cannot be said to be heard.