維摩經玄疏 1.105

1.105

此即但約世界悉檀具起十二部經。餘三悉檀各起十二部經，類「世界」可知。佛用此十二部為言教之本，說一切漸、頓諸教也。故《智度論》云「四悉檀攝得十二部經」，意在此也。

This is merely in terms of the worldly siddhānta fully giving rise to the twelve divisions of sūtras. That the remaining three siddhāntas each give rise to the twelve divisions of sūtras can be known by analogy with the "worldly [siddhānta]." The Buddha uses these twelve divisions as the root of verbal teaching to expound all the gradual and sudden teachings. Therefore the Dazhidulun says, "The four siddhāntas subsume the twelve divisions of sūtras"; this is the meaning intended.