維摩經玄疏 6.25

6.25

Answer: It fully possesses both meanings. As for being non-empty because it is existent: because it is the nature of wisdom, it is not empty. As for being called non-empty because of non-existence: the principle of the dharma-nature of ultimate truth is precisely empty, and because this emptiness is ultimately ungraspable, it is called non-empty. Saying 'non-empty' means that it is not the emptiness of the dharma-nature of the ultimate truth. Therefore, the Mahāprajñāpāramitopadeśa says: 'Emptiness has two kinds: first, mere emptiness; second, ungraspable emptiness.' The śrāvaka attains only mere emptiness, whose wisdom is like the light of a firefly; the bodhisattva attains mere emptiness and attains ungraspable emptiness, whose wisdom is like the light of the sun. The two vehicles alike attain mere emptiness, hence it is called 'similarity'; the bodhisattva attains ungraspable emptiness, which is called 'difference.' It is like digging earth: removing the earth, one reaches mud; if removing the mud is complete, one reaches water.