俱舍論頌疏論本 17.87

17.87

釋曰：一業引一生者，釋引業也，舊云總報業也。依薩婆多宗，但由一業唯引一生，若許一業能引多生，時分定業應成雜亂。若此一生多業所引，應眾同分分分差別，以業果別故（分分差別者，謂數死數生也），故知一業唯引一生。

Explanation: "One karma projects one life" explains projectile karma, formerly called 'general-retribution karma'. According to the Sarvāstivāda school, only one karma projects solely one life. If one were to allow that one karma could project many lives, then karma with a determined time would become disordered. If this one life were projected by many karmas, there would have to be part-by-part distinctions within the genre-counterpart, because the karmic fruits are distinct (part-by-part distinctions means dying repeatedly and being born repeatedly). Therefore, it is known that one karma projects only one life.