成唯識論演祕 2.421

2.421

按彼論云：若爾所說同分是何，即如是類諸行生時，於中假立人同分等，如諸穀麥等同分也。

According to that treatise: 'If so, what is the generic similarity spoken of? It is merely nominally established as human generic similarity and so forth when saṃskāras of such classes arise, just like the generic similarity among grains of barley, wheat, and the like.'