成唯識論述記 2.488

2.488

述曰：此舉有法及二種因，「色、心等所顯性」者，謂色亦能顯色、心等，如燈、日、月照色等法，以色顯色；以聲詮色、心；以身、語業表善、惡色、心等，此即以色表色、心也。心顯色、心，其理可解。

The Commentary states: This presents the subject (dharmin) and two reasons (hetu). "Natures revealed by form, mind, and so forth" means that form can also reveal form, mind, and so forth; just as lamps, the sun, and the moon illuminate forms and other dharmas, revealing form by means of form; sound expresses form and mind; physical and vocal actions manifest wholesome and unwholesome form, mind, and so forth; this is manifesting form and mind by means of form. That mind reveals form and mind is readily understood.