大乘百法明門論開宗義決 1.89

1.89

異熟之識熟屬種子者。若以異熟屬種子上。種與現識體既不同。乃是異熟種家之識故名異熟。依主釋也。

Regarding "the consciousness of maturation, where maturation belongs to seeds": If one attributes maturation to the seeds, since the entities of seeds and the active consciousness are different, it is the consciousness belonging to the seeds of maturation, and hence is called vipāka[vijñāna]—a tatpuruṣa compound.