成唯識論述記 3.305

3.305

The Commentary states: This refers to the mind produced through mental application, which is a mind of deliberation, namely, the sixth and seventh consciousnesses, because they arise in accordance with their own conceptual discrimination and mental application. Because of this, when the sixth and seventh take non-existence and the like as objects, the nimittabhāga of the image has no real substance and does not necessarily have utility. Nor is it that because they are called conceptual discrimination, the substance of the transformed object is definitely non-existent, for they also take existent things as objects. Or: the first includes the whole of the five and the eighth, and a small part of the sixth; the latter includes the whole of the seventh and extends to a small part of the sixth. This interpretation accords with the treatise's text on 'having utility,' etc.