俱舍論疏 5.182

5.182

論「非顯諸行至亦可了知」，第二明經所說非剎那也。凡言相者，表其體性令人了知，經言亦可了知，明非不可知也。一剎那中生等四相既不可知，定是非經所說。

On the passage in the śāstra from “It does not reveal of all formations…” to “…are also discernible”: The second clarifies that what the sūtra states does not concern a moment. In general, whenever one speaks of a ‘characteristic,’ it manifests its nature and makes people discern it; since the sūtra says they are ‘also discernible,’ it clarifies that they are not indiscernible. Since within a single moment the four characteristics of arising and so forth are indiscernible, they are definitively not what the sūtra spoke of.