八識規矩補註 2.36

2.36

此言第八現識如水，八識現、種如波，境等四緣如風。若四緣之風恒擊第八現水，則常起八識種、現之波。喻中多風至多波生，少風至少浪起；法中多緣多識生，少緣少識起；故《楞伽》云「如海遇順風」等，已見上文。

This says that the eighth, the manifest consciousness, is like water; the manifest activity and seeds of the eight consciousnesses are like waves; and the four conditions, such as cognitive objects, are like the wind. If the wind of the four conditions constantly strikes the manifest water of the eighth, then it constantly gives rise to the waves of the seeds and manifest activity of the eight consciousnesses. In the metaphor, when much wind arrives, many waves arise; when little wind arrives, few waves arise. In the doctrine, through many conditions many consciousnesses arise; through few conditions few consciousnesses arise. Thus the Laṅkāvatāra says, "Just as the ocean encountering a favourable wind," etc., as seen above.