成唯識論述記 5.909

5.909

述曰：下釋開合，以苦、樂受，於身、心各別故。所以者何？謂在五識即楚利逼切，明利適悅，名苦、樂；在意稍降逼切，如可適悅，名憂、喜受。身、心異相也。

The Commentary states: Below is the explanation of division and combination: because the feelings of pain and pleasure are distinct in body and mind. Why is that? In the five consciousnesses, severe torment and clear, sharp gladdening are called pain and pleasure; in the mind, slightly less severe torment and agreeable gladdening are called grief and joy. These are the different characteristics of body and mind.