瑜伽師地論略纂 8.197

8.197

論解證成道理中云「謂作是思：云何今者作意思惟能對治法，可於能治所緣境界煩惱當生」者，此中意云：外不淨境，名能對治，治欲貪故。由緣外不淨色故，必能治所緣淨境煩惱當生。謂立量云：緣不淨時必能治欲貪，以緣能治故，如緣無相時能遣有相。

Where the treatise explains the reasoning of demonstration, saying, “Namely, one reflects thus: ‘How could it be that now, by bringing to mind and contemplating the counteractive dharmas, afflictions would arise toward the objective spheres that are the object of the counteractive [state]?’”: the intention here says that external foul objects are called the counteractive, because they counteract sensual desire. By taking external foul colors as object, it is certain that the afflictions toward clean objects that are the object of the counteragent will arise [to be subdued]. Formulating a formal argument: when taking the foul as object, one can definitely counteract sensual desire, because of taking the counteragent as object, just as when taking the signless as object one can dispel the signed.