唯識二十論述記 1.279

1.279

述曰：若執唯識，亦計所執，除入法空，名法無我。若不執時，此唯識體，性離言故，非除入空。

The Commentary says: If one grasps vijñapti-mātra, that too is conceptually grasped; eliminating it and entering into phenomenal emptiness is called the selflessness of phenomena. When one does not grasp it, the substance of this vijñapti-mātra is by nature ineffable, and thus is not eliminated to enter emptiness.