唯識二十論述記 1.102

1.102

述曰：下第四難，頌第四句，「作用不成」，於中有三難，此即第一，翳髮等無實用。「復有何因」言，通三難問，及申三難竟。論云：餘髮等物其用非無，通上三難。謂既無實境，許有此識生，有何所以，有眩翳者所見髮、蠅等，無髮、蠅等用；無眩翳者，所見髮、蠅等，有髮、蠅等用。髮有為髻等用，蠅有附食等用也。量云：眩翳所見應有實用；執無實境此識生故；如餘髮等。

The Commentary says: Below is the fourth objection, corresponding to the fourth line of the verse: 'causal efficacy is not established.' Within this there are three objections, and this is the first: cataract-hairs and the like lack real function. The phrase 'furthermore, for what reason' applies as a question to all three objections, down through the end of stating the three objections. The treatise states: 'while other hairs and such things are not without their functions,' which applies to the three objections above. That is, since there is no real object, yet you grant that this consciousness arises, what is the reason that the hairs, flies, and so forth seen by those with cataracts lack the functions of hairs, flies, and so forth, while the hairs, flies, and so forth seen by those without cataracts have the functions of hairs, flies, and so forth? Hair has the function of forming a topknot and the like, and flies have the function of alighting on food and the like. The inference says: That which is seen by one with cataracts should possess real function; because this consciousness arises while maintaining that there is no real object; just like other hairs and so forth.