成唯識論演祕 5.104

5.104

按彼論云：若那落迦等中，他所映奪，不苦、不樂受與純苦無雜受俱時而轉，當知此受被映奪，故難可了知，如那落迦等中，一向苦受俱轉。

According to that treatise: In the hells and so on, eclipsed by other [factors], neither-unpleasant-nor-pleasant sensation occurs simultaneously with pure, unadulterated unpleasant sensation; you should know that because this sensation is eclipsed, it is difficult to perceive clearly, just as in the hells and so on, it occurs simultaneously with purely unpleasant sensation.