俱舍論疏 25.148

25.148

論「又依可屈伏不可屈伏故」，第二釋也。先可屈伏，但名根，不得名力。復不可屈伏，是力義故，名為力也。

On the Śāstra's statement: "Furthermore, based on being yieldable and not yieldable": This is the second explanation. When it is initially yieldable, it is only called a faculty and cannot be called a power. When it is further unyielding, that is the meaning of 'power', so it is named 'power'.