成唯識論述記 8.437

8.437

述曰：此第四問也。何緣果合立生、老死？於所引位乃別開立識等五支？雖種現殊，而體無別，故相對問。

The Commentary states: This is the fourth question. For what reason are the results combined and established as birth and aging-and-death, whereas in the stage of what is projected, they are divided and established as the five factors of consciousness and so on? Although seeds and actual manifestations differ, their entities are not distinct; hence they are questioned in mutual contrast.