大般涅槃經義記 9.209

9.209

九難破道因成無聖道。於中先舉二種道因，謂聞及思。修即是道，故不舉修。下就設難。先難有因，「此二因緣若有因生，所從因緣復從誰生？如是展轉有無窮過」。下難無因，「若此二事不從因生，一切眾生何故不得」。

Ninth, challenging and refuting the cause of the path to establish that there is no noble path. Therein, it first cites two kinds of causes of the path, namely hearing and thinking; cultivating is the path itself, so it does not cite cultivation. Below, it raises challenges: First, challenging that it has a cause: "If these two causal conditions arise from a cause, from what cause do their resulting causal conditions again arise? Iterating in this way incurs the flaw of infinite regress." Below, it challenges that it is uncaused: "If these two matters do not arise from a cause, why do all sentient beings not attain them?"