成唯識論述記 2.71

2.71

述曰：舉月為難，應立量云：汝和合色處，設許是眼識之所緣，非是緣；以彼都無實體性故；如第二月。第二月彼計亦是假，不生五識，唯意識所緣。《觀所緣緣論》頌云：「和合於五識，設所緣非緣，彼體實無故，猶如第二月。」經部第二月亦非五所緣，今以為喻者，意取少分。

The Commentary states: Raising the [second] moon as an objection, one should set up the syllogism: Your combined visible matter, even granted to be the object of visual consciousness, is not its condition (thesis); because it completely lacks a real entity (reason); like a second moon (example). The second moon, in their doctrine, is also nominal, does not produce the five consciousnesses, and is cognized solely by mental consciousness. The Ālambanaparīkṣā verse says: 'The combination, with respect to the five consciousnesses, / Granted it is an object, is not a condition; / Because its entity is truly non-existent, / Just like a second moon.' For the Sautrāntika, a second moon is also not an object of the five [consciousnesses]; using it now as an example is intended to take a partial aspect.