大般涅槃經義記 7.359

7.359

自下第五於前義中隱者重釋。何故須然？如來昔說身智盡處以為涅槃，今說諸佛煩惱盡處是其涅槃，二言相乖，故須重釋。又佛昔說煩惱斷處身為涅槃，今此宣說涅槃如空，體無所有。兩言相異，故須辯釋。

Below is the fifth [point]: what was hidden in the preceding meanings is explained again. Why must this be so? Formerly the Tathāgata spoke of the place where body and wisdom are exhausted as nirvāṇa, but now says that the place where the buddhas have exhausted defilements is their nirvāṇa; the two statements contradict each other, and hence it must be explained again. Furthermore, the Buddha formerly said that the body at the place where defilements are severed is nirvāṇa, but now here declares that nirvāṇa is like space, its substance having nothing whatsoever. The two statements differ, and hence they must be analyzed and explained.