成唯識論述記 5.816

5.816

述曰：返成耳識，若在定中唯意緣聲，耳不聞聲者，於此音聲，定中耳識不領受故，後時不應為此聲故而出於定。後時既為聲故出定，明在定內耳與意俱同念聞聲。破小乘等立一，量云：如汝所為欲聞聲末後出定之意識，應不即聞聲時出定；不聞聲故；如未聞聲之定意識。故知返成聞聲方出。

The Commentary states: This proves the ear-consciousness by the counter-thesis: if, while in concentration, only the mental consciousness took sound as its cognitive object and the ear did not hear the sound, then because the ear-consciousness within concentration did not apprehend this sound, it would not later emerge from concentration on account of this sound. Since it subsequently emerges from concentration on account of the sound, it is clear that within concentration the ear and the mental consciousness hear the sound together in the very same moment of thought. Refuting the Hīnayāna and other schools, an inference (anumāna) is formulated: 'The mental consciousness that, as you assert, emerges from concentration at the very end wishing to hear a sound, should not emerge from concentration precisely at the time of hearing the sound; because it does not hear the sound; just like the concentrated mental consciousness that has not yet heard the sound.' Thus we know, by proving the counter-thesis, that one emerges only after hearing the sound.