肇論疏 3.35

3.35

搜謂搜括，玄謂玄妙。搜括玄妙之所在，故云搜玄也。有名曰論云涅槃既不出有無下，牒前語也。不在有無則不可於有無而得之下，定宗也。求之無所使應都無然復不無其道，既無定求之處，則應都無涅槃，而復不得云無涅槃也。其道不無則幽途可尋，言幽玄途略可尋求耳。所以千聖同轍，千聖言多佛，多佛謂諸佛。諸佛皆同此轍。轍，車轍，喻正道也。諸佛皆遵此轍，無有虛返。虛返者，謂前無涅槃，然後却返也。其道既有下，既有涅槃之道，而復言其不出不在，必應有意，願欲聞也。

"Searching" means seeking out and gathering; "profound" means the dark and marvelous. It means searching out the location of the dark and marvelous; hence it is called "Searching the Profound".

[The text states:] "The Possessor of Names says: 'The treatise says that since nirvāṇa does not transcend existence and non-existence'" and so on: this recaps the previous words.

"If it is not within existence and non-existence, it cannot be attained in existence and non-existence": this establishes the thesis.

"If seeking it yields no location, it should imply that it is completely non-existent; yet its Way is not non-existent": since there is no definite place to seek it, it would follow that there is no nirvāṇa at all; yet one cannot say that there is no nirvāṇa.

"Since its Way is not non-existent, the profound path may be sought": this means that the dark and profound path can roughly be sought.

"This is why the thousand sages follow the same tracks": "thousand sages" refers to many Buddhas; "many Buddhas" means all Buddhas. All Buddhas follow this same track. "Track" (轍) means a wagon rut, a metaphor for the correct path. All Buddhas follow this track and none return in vain. "Returning in vain" means that there is no nirvāṇa ahead, and so they turn back.

"Since its Way exists" and so on: since the Way of nirvāṇa exists, yet you also say that it neither transcends nor is present [within them], there must surely be a meaning to this; I wish to hear it.