金剛般若經依天親菩薩論贊略釋秦本義記卷上 1.68

1.68

[Sūtra:] "The Dharma preached by the Tathāgata can neither be grasped nor expressed; it is neither dharma nor non-dharma." The fourth is the explanation. Here it merely says that the teaching of the nirmāṇakāya is not the absolute truth; it does not mean there are no verbal expressions at all. Therefore the sūtra says: "The Dharma preached by the Tathāgata can neither be grasped nor expressed." The listener cannot grasp it making notions of existence or non-existence, and the preacher cannot preach it making notions of existence or non-existence. Why is this? Because it is neither dharma nor non-dharma. "Dharma" [in non-dharma] means false dharmas have no substance; "non-non-dharma" means that suchness is truly existent.