成唯識論述記 7.403

7.403

述曰：論主答曰：如眼識等於自所緣色等，一已能了，餘眼識更生便無用故，所以不生。

The Commentary states: The author of the treatise answers: Just as the eye-vijñāna and so forth have already discerned their own cognitive object, such as form, if another eye-vijñāna were to arise again it would be useless; therefore it does not arise.