大般涅槃經義記 3.151

3.151

觀察驗中，初先立喻、次合、後勸。喻中，准合具應有三：一邪正交參喻、二愚人不別喻、三智人能別喻。今此文中但有前二，略無第三。

In examining by means of observation, it first establishes a simile, next makes the application, and afterward provides exhortation. Within the simile, matching the application, there should fully be three: first, the simile of the intermingling of the false and the true; second, the simile of foolish people not distinguishing; third, the simile of wise people being able to distinguish. Now, in this text, there are only the former two, with the third omitted in brief.