維摩經略疏垂裕記 10.94

10.94

十八、明相。荊溪云：四種空種等，亦先立，次四種乃至不二，正釋也。言「內外皆空」者，即體空也，即是中道空也，具如前釋。

18. Mark of Light. Jingxi says: The four kinds of emptiness, etc., are also first established; next, "the four kinds down to non-duality" directly explains it. The statement "internal and external are both empty" is essential emptiness, which is the middle-way emptiness, fully as explained earlier.