成唯識論述記 3.152

3.152

若緣名變，即唯影像，心上現者，有漏諸識等各自相分是。准此應思一切諸法，或復作三：亦有執故，名之為變，即根、種等具二變義；外器唯一，七識亦一。言不變者，依此二門、三門可解。

If it is named transformation in the sense of cognitive representation, then it is solely the mental image appearing upon citta, which is the respective nimittabhāga of each contaminated consciousness and the like. All dharmas should be considered in this light. Alternatively, a threefold schema can be made: because there is also appropriation, it is called transformation, meaning that the sense faculties, seeds, and so forth possess both meanings of transformation; the external receptacle world has only one, and the seven consciousnesses also have only one. When it is said not to transform, it can be understood based on these two approaches or three approaches.