成唯識論述記 7.96

7.96

述曰：彼意地苦，與憂相似，有分別故，總說為憂，即攝彼苦。餘趣憂、苦，各在一處，勢不相似，何緣不說？此即意中有苦受師義。

The Commentary states: Pain in that mental ground is similar to grief because it involves conceptual discrimination; hence it is collectively called grief, which thereby subsumes that pain. In the other destinies, grief and pain are each in separate locations and their dynamics are not similar; for what reason would they not be mentioned? This is the position of the master who maintains that there is painful sensation in the mental consciousness.