成唯識論述記 7.393

7.393

述曰：以外喻識。如多波浪、鏡像，以一大海、一鏡為依，起多浪、多像，故依一本識心，多識俱起。此並五十一、七十六、《解深密》文。然有此文，此八證中業用證也，一念之中有四業故。而今有人云：八識不異如浪、像故，今說不然，彼依少分相依道理為喻，非盡理故。

The Commentary states: Using an external analogy for consciousness. Just as multiple waves or mirror reflections, relying on a single great ocean or a single mirror, give rise to multiple waves or multiple reflections, so relying on the single root consciousness mind, multiple consciousnesses arise simultaneously. These are all texts from fascicles fifty-one and seventy-six [of the Yogācārabhūmi] and the Saṃdhinirmocana. Indeed, with this text, it is the proof of functional activity among the eight proofs, for within a single moment there are four functional activities. But nowadays someone says: 'The eight consciousnesses are not distinct, just like waves and reflections.' We now state that this is not so: that is an analogy based on a partial principle of mutual dependence, not fully capturing the principle.