大般涅槃經義記 6.53

6.53

下次却廣第二門中若性若相，「復次，菩薩亦見亦知」總以標舉。下別顯之，常、無常等是其世諦，法相麁顯易可辨了，知之分明故名為見。無常、苦等是生死法，常、樂、我等是佛方便涅槃之法，如來法身、眾生佛性深細難測，知之難明故不名見，但說為知。於中先明知佛法身，後明知性。

Next, it turns back to extensively explain the second gate, nature and marks: "Furthermore, the bodhisattva both sees and knows" summarizes and introduces it. Below, it distinguishes them: permanence, impermanence, and so forth are conventional truth; the marks of dharmas are coarse and apparent, easy to discern and understand, and knowing them clearly is therefore called seeing. Impermanence, suffering, and so forth are dharmas of birth and death; permanence, bliss, self, and so forth are the dharmas of the Buddha's nirvāṇa of expedient means; the Tathāgata's dharmakāya and sentient beings' buddha-nature are profound, subtle, and difficult to fathom; knowing them is difficult to make clear, so it is not called seeing, but merely spoken of as knowing. Therein, it first clarifies knowing the Buddha's dharmakāya, and afterwards clarifies knowing the nature.