仁王護國般若波羅蜜多經疏 2.7

2.7

解曰：明能照智稱境而觀，非有非無通境智矣。叡法師云：「萬物非無，宗之者無相；虛宗非有，照之者無心。」故聖人以無心真智照無相虛宗，內外兩冥、境智俱寂即其照也。從此第二徵其所以。

The commentary explains: Clarifying that the contemplating cognition observes in accord with the object, 'neither existent nor nonexistent' applies to both object and cognition. Dharma Master Rui said: 'The ten thousand things are not nonexistent; those who take them as primary have no marks. The empty essence is not existent; those who contemplate it have no mind.' Therefore the sage contemplates the signless empty essence with the mindless real cognition; when both inner and outer are obscured, and object and cognition are both quiescent, that is precisely the contemplation. From here, second, he inquires into the reason.