肇論新疏 2.93

2.93

會經正意。將無者，豈非也。既不約性空及所知云清淨，然經言清淨有二意：一智體真淨非知見故、二本無惑取之知故。既本無矣，難以知名。豈唯下，恐疑者聞前云性淨無知，謂兀然絕照。故今遣云：以知無知相故、本無惑取故，知即無知也。

This unifies the correct meaning of the sūtra. "Could it not be" (jiangwu) means "is it not." Since purity is not spoken of in terms of empty nature or the known, the sūtra's statement of purity has two meanings: first, the essence of wisdom is truly pure and not [conventional] knowing and seeing; second, it is originally devoid of the knowing that grasps in delusion. Since it is originally non-existent, it is difficult to designate it by the name "knowing." From "How could it merely be..." onward: fearing that a doubter hearing the earlier statement that the nature is purely without knowing might think it is inertly devoid of illumination, he now dispels this by saying: because knowing lacks the mark of knowing, and is originally devoid of delusive grasping, knowing is itself without knowing.