大般涅槃經義記 6.21

6.21

文別四者：一觀內中無有父母、眾生、壽命，乃至無彼妄情所討常、樂、我、淨。二於此空中無佛、法、僧。三於此空中無外財物。問曰：內中無外財物應是互無，今以何義說為理空？釋言：內中無外財物實是互無，但今於彼內空之中無外財物，故是理空。下外空中無內物等類皆同爾，應當知之。四於此空中無其佛性，是內法中雖有佛性窮實明有，而是佛性非內非外，隨相說無。今此正明內中無人，未辯餘義，故無佛性，是中唯應說性非內非外乘論。

As for the text having four parts: first, contemplating that within the internal there are no parents, sentient beings, or life-spans, up to the absence of the permanence, bliss, self, and purity sought by deluded feelings. Second, within this emptiness there is no Buddha, Dharma, or Saṅgha. Third, within this emptiness there are no external wealth or objects. Question: The absence of external wealth and objects within the internal should be mutual non-existence; by what meaning is it now spoken of as the emptiness of principle? Explanation: The absence of external wealth and objects within the internal is indeed mutual non-existence, but now within that internal emptiness there are no external wealth and objects, so it is the emptiness of principle. Below, the absence of internal things within external emptiness is likewise the same by analogy, as should be understood. Fourth, within this emptiness there is no buddha-nature; although buddha-nature exists within internal phenomena when exhaustively clarified in terms of reality, that buddha-nature is neither internal nor external, and is spoken of as non-existent in accordance with marks. Here, specifically clarifying that there is no person within the internal without yet explaining other meanings, it is therefore without buddha-nature; herein one should only speak of its nature being neither internal nor external by way of digression.