因明入正理論疏 2.45

2.45

問：「敵者不解聲有無常，何得以瓶而為同品？」答：「兩家共許，所作同故，因正同品。立者所立本立無常，故舉於瓶為宗同品，亦無過也。」

Question: 'The opponent does not understand that sound possesses impermanence; how can a pot be taken as a sapakṣa?' Answer: 'Because both parties mutually accept that they are the same in being produced, it is the primary sapakṣa of the reason. What the proponent seeks to establish is originally impermanence; therefore, adducing a pot as the sapakṣa of the thesis is also without fault.'