維摩經略疏 9.70

9.70

「德守」者，三德之法守持無失，實相之理愛護堅嚴，從此為名。「我我所為二」，既無我則不得所。一往此語似如空門，何得是不二門。但別教之中具有四門，或隨性欲入道不同，或為赴機化物有異，應須四門引接，不但一非有非無之門。此雖似空門，終是不二即中之空。若二乘斷我見諦得入涅槃，此但空我、不空我所得涅槃故，故言「我生已盡所作已辦」，當知未空於所也。今言空者，如上文云「我及涅槃是二皆空」，我空故即是空生死，涅槃空故即是空所，故言「是二皆空，空病亦空」，二邊雙遣則入不二法門。

'Guṇagupta' (Virtue-Protected): he guards and upholds the dharmas of the three virtues without lapse, and cherishes and protects the principle of true reality with firm solemnity; he takes his name from this.
'Self and what belongs to the self (mine) are dual': since there is no self, what belongs to it cannot be apprehended. At first glance, these words resemble the gate of emptiness; how can it be the gate of non-duality? However, within the distinct teaching the four gates are fully present. Whether entering the path differently according to dispositions and desires, or having differences to respond to capacities and convert beings, it is necessary to use four gates to guide and receive them, not only the single gate of neither existence nor non-existence. Although this resembles the gate of emptiness, it is ultimately the emptiness of non-duality that is itself the Middle. If the two vehicles sever the self, see the truth, and attain entry into nirvāṇa, this merely empties the self and does not empty what belongs to the self, namely the attained nirvāṇa. Hence they say: 'My births are exhausted, what was to be done is completed'; one should know that they have not yet emptied what belongs to the self. Now, speaking of emptiness, as the text above says: 'Self and nirvāṇa—these two are both empty.' Because the self is empty, birth-and-death is emptied; because nirvāṇa is empty, what belongs to the self is emptied. Therefore it says: 'These two are both empty, and the illness of emptiness is also empty.' When both extremes are dispatched together, one enters the dharma gate of non-duality.