成唯識論述記 7.379

7.379

述曰：却難外曰：如欲界有情，若上他界分，他無漏分心現在前位，如何可說自分欲界有情，乃至無色界亦爾？既雙質已，今為正通。

The Commentary states: Turning the objection against the opponent: for instance, in the case of a sentient being of the desire realm, if a mind of a superior, different realm-division, or a mind of a different unwholesome or undefiled division is currently present, how could one be said to be a sentient being of one's own division of the desire realm, and likewise up to the formless realm? Having thus cross-examined both points, he now provides the correct resolution.