維摩經略疏 9.86

9.86

「明相」者，四種者四大種，與空種為二。四種圍虛空而住，內外皆空。皆空即無四種，四種與空種無異，故泯於空有之種，即入不二法門。

"Mark of Luminosity" (Prabhāketu): the four elements are the four great elements, which form two with the element of space. The four elements abide surrounding empty space, and the internal and external are all empty. Being all empty, there are no four elements; the four elements and the element of space are not different. Therefore, effacing the elements of emptiness and existence, one enters the Dharma door of nonduality.