成唯識論述記 8.223

8.223

述曰：種子必無等無間緣、所緣緣起，此之二緣，四緣之中，位居中故，以此二緣待心、心所為果方能生故，種非心等，故非二緣果。

The Commentary states: Seeds definitely do not arise from the immediately preceding condition (samanantara-pratyaya) or the objective condition (ālambana-pratyaya). These two conditions, among the four conditions, occupy the middle positions, because these two conditions can produce only by awaiting citta and caitasikas as their fruit. Since seeds are not citta and so forth, they are not the fruit of these two conditions.