十不二門指要鈔 1.25

1.25

初、例本妙。若本若迹各論十妙而不同者，但是互有離合故也。迹因具明境智行位四者，離因故迹；果惟明三法一妙者，合果故本。中不云境等，唯明一本因妙者，合因故；本果之外，更立本國土、本涅槃、本壽命者，離果故。故知唯云因妙必具境等，唯云三法必具國土等，若知因果不殊，自他豈應有異？以本初坐道場時亦遍赴物，豈不現通說法，豈無眷屬獲益邪？應知久近雖異，皆以三千俱空假中而為大綱，故云不思議一。

First, the analogy with the origin subtleties. That ten subtleties are discussed separately in both the origin and the trace and yet differ is only because they mutually separate and combine. That the trace cause fully clarifies four [aspects]—object, wisdom, practice, and stages—is because it separates the cause; that the trace effect clarifies only the single subtlety of the three dharmas is because it combines the effect. That in the origin [the text] does not mention the object and so forth, but clarifies only the single origin subtle cause, is because it combines the cause; that outside of the origin effect it further establishes the origin realm, origin nirvāṇa, and origin lifespan is because it separates the effect. Thus one should know that only stating the subtle cause necessarily encompasses the object and so forth, and only stating the three dharmas necessarily encompasses the realm and so forth. If one knows that cause and effect are not distinct, how could self and other differ? Because when the origin [Buddha] first sat at the place of awakening he also universally responded to beings, how could he not display supernormal powers and preach the Dharma? How could there be no retinue obtaining benefit? One should know that although remote and recent differ, both take the three thousand realms being simultaneously empty, provisional, and middle as their general framework; hence it says 'inconceivably one.'