成唯識論述記 5.146

5.146

述曰：意識緣五塵與五同故，名緣共境。第七緣五塵，亦應如意名緣共境。

[The Commentary states:] Because mano-vijñāna takes the five sensory dusts as cognitive objects in common with the five [sense consciousnesses], it is called taking a shared realm as cognitive object. If the seventh consciousness took the five sensory dusts as cognitive objects, it should also be called taking a shared realm as cognitive object, like mano-vijñāna.