俱舍論疏 5.178

5.178

論「若爾何故至亦可了知」，有部救也。既經言有三有為之有為相，即是屬主之名。前是本法、後是其相，故知法外別有四相。

On the passage in the śāstra from “If so, why…” to “…are also discernible?”: The Vaibhāṣikas rescue their position. Since the sūtra says there are three characteristics of the conditioned belonging to the conditioned, this is a genitive phrase designating possession. The former is the underlying phenomenon, and the latter is its characteristic; therefore, we know that apart from the phenomenon, there are separately the four characteristics.