維摩經玄疏 3.50

3.50

一、四宗名義，言方似滯者，彼不依四不可說，用四悉檀說，則成滯也。

First, as for the terms and meanings of the four tenets seeming rigid in their phrasing: because they do not rely on the four inexpressibles and preach using the four siddhāntas, they become rigid.