俱舍論疏 6.105

6.105

論「此於諸地至由同類故」，答所以也。一如客住故、二不墮界攝、三非諸地愛執為已有。由此三因，地雖不同，展轉為因，由同類故。

The treatise says: "These, regarding the stages... because of being of the same kind." This answers the reason: first, because they dwell like guests; second, because they do not fall under the inclusion of the realms; third, because they are not grasped by craving of the various stages as belonging to oneself. By virtue of these three causes, although the stages are different, they mutually serve as causes, because of being of the same kind.