大般涅槃經義記 9.126

9.126

「如海」已下是第三段當法正嘆，先喻、次合，有難解者下重分別。喻中先舉，次列八名，下辨其相。一一之中各有三事：一眾生福力令海漸深易可趣入，二順風行從畔漸遠亦名漸深，三河水入中遂水漸進亦名漸深。餘中二事，文略不辨。

From "Like the ocean" onward is the third section, which directly praises the teaching itself: first by metaphor, next by application, and what is difficult to understand is subsequently distinguished again. In the metaphor, it first introduces it, next lists the eight names, and below distinguishes their marks. Within each single one there are three matters: first, the power of sentient beings' merit causes the ocean to become gradually deeper so that it can be easily entered; second, moving with the wind gradually farther from the shore is also called becoming gradually deeper; third, when river waters enter it, following the water it gradually advances, which is also called becoming gradually deeper. The other two matters are abridged in the text and not distinguished.