維摩經玄疏 6.68

6.68

一、明四悉檀起三藏教四門者，即是生生不可說，有四悉檀因緣，亦可得說。

First, explaining the four siddhāntas generating the four doors of the Tripiṭaka teaching: that is, the arising of arising cannot be spoken of, yet through the conditions of the four siddhāntas, it may also be spoken of.