成唯識論演祕 2.14

2.14

Answer: It is simply because one's own perceptual field restricts one's own faculties and consciousnesses, preventing them from operating upon other perceptual fields. Or, when operating in conjunction with their own perceptual fields, they cannot arise with respect to other perceptual fields; hence it is called 'obstruction.' Therefore, the Abhidharmakośabhāṣya says: 'Why are the eye and other [faculties] said to have resistance when operating upon their own perceptual field and intentional object? Because they do not operate beyond it, upon others.' Or again, obstruction has the meaning of conjunction, meaning that phenomena such as the eye operate in conjunction with their own perceptual fields and their own intentional objects.