維摩經玄疏 6.75

6.75

四、明用四悉檀起圓教四門，類三藏教可知，具釋並在四教大本。

Fourth, explaining the use of the four siddhāntas to generate the four doors of the perfect teaching: this can be known by analogy with the Tripiṭaka teaching; the detailed explanation is fully found in the primary text on the four teachings.