維摩經玄疏 5.5

5.5

一、修多羅名含法本義者，大聖知一切皆不可說，以四悉檀因緣而有言教者，若世界悉檀說，即為一切論本；若為人、對治兩悉檀說，即為行本；若第一義悉檀說，即為理本，故修多羅含「法本」義也。

First, the name sūtra containing the sense of "root of dharmas": the Great Sage knows that all is ineffable, yet through the causes and conditions of the four siddhāntas there are spoken teachings. If spoken through the mundane siddhānta, it is the root of all treatises; if spoken through the for-persons and curative siddhāntas, it is the root of practice; if spoken through the paramārtha siddhānta, it is the root of principle. Therefore sūtra contains the sense of "root of dharmas".