維摩經玄疏 5.7

5.7

三、明修多羅含涌泉義者，此從譬以明義，如泉涌流，滔滔無竭。佛用四悉檀說法，文義無盡，法流不絕，津潤萌芽，三草兩木，一地所生，皆得增長，故修多羅含「涌泉」義也。

Third, clarifying that sūtra contains the sense of "bubbling spring": this illuminates the meaning by way of a metaphor, like a spring bubbling and flowing, surging without exhaustion. The Buddha uses the four siddhāntas to preach the Dharma, with inexhaustible text and meaning, the flow of Dharma never ceasing, moistening the sprouts so that the three grasses and two trees, born of the one earth, all attain growth. Therefore sūtra contains the sense of "bubbling spring".