俱舍論疏 16.58

16.58

「論曰至異此即無」，釋加行中重心即有無表，異此則無無表。其表定有，若無表業非加行故。

[On the passage] from "The Śāstra says" up to "otherwise there is none": this explains that during the prayoga, if the mind is serious, there is non-manifest [action], whereas otherwise there is no non-manifest [action]. Its manifest action is definitely present, because without manifest action it would not be a prayoga.