楞伽阿跋多羅寶經註解 1.703

1.703

此詶無二之問。先約事示其二相，陰熱、長短、黑白之相待對宛然，不得不二。又曰一切法無二者，約理言也，以其理一，融彼事異，則一切法無二也。言非於涅槃等者，生死、涅槃本來平等，非涅槃外別有生死，非生死外別有涅槃，彼即外也。然此二者不二而二、二而不二。若不了此而謂有異相因，則各有自性，故說無二以一之。既了此二無二，則一切法無不然也。是故下，總結勸。

This answers the question on non-duality. First, referring to phenomena, it shows their dual marks: shade and heat, long and short, black and white are vividly matched against one another, so that they cannot but be dual. Furthermore, saying that all dharmas are non-dual refers to the principle: because their principle is one, it integrates those phenomenological differences, so that all dharmas are non-dual. The words 'neither is saṃsāra outside of nirvāṇa…' mean that saṃsāra and nirvāṇa are fundamentally equal; outside of nirvāṇa there is no separate saṃsāra, and outside of saṃsāra there is no separate nirvāṇa—'outside' meaning external. Yet these two are dual while non-dual, and non-dual while dual. If one does not comprehend this and asserts that different marks have causes, then each would have its own svabhāva; therefore non-duality is spoken of to unify them. Once one understands that these two are non-dual, then all dharmas are likewise so. 'Therefore…' below summarizes and exhorts.