大乘百法明門論開宗義決 1.52

1.52

三軌唯有為要成因緣方生解等者。謂有為法方成因緣。仗因託緣方能生解。故軌則義唯在有為。其無為者既都無相。心不能緣不成因緣。不能生解不成軌義。不失自性持義則通。雖後得智有漏意識亦緣無為而生智解。但是影像不是親緣。不同正智故不為例。

Regarding "third, measure applies only to conditioned things, requiring causes and conditions to produce understanding," etc.: This means that only conditioned dharmas constitute causes and conditions; relying on causes and trusting in conditions, they can produce understanding. Hence the meaning of "measure" lies solely in conditioned dharmas. As for unconditioned dharmas, since they lack characteristics altogether, the mind cannot take them as objects, they do not constitute causes and conditions, and they cannot produce understanding; thus they do not fulfill the meaning of "measure." Not losing their intrinsic nature, however, fulfills the meaning of "maintaining." Although the subsequent wisdom and defiled mental consciousness also take the unconditioned as object and generate understanding, this is merely through an image and not a direct apprehension; unlike correct wisdom, it cannot serve as a counter-example.