成唯識論演祕 2.14

2.14

答：祇為自境拘自根、識，不令於餘境等轉故。或自境等和合轉時，於餘境等而不得起故，名為礙。故《俱舍論》云：云何眼等於自境界所緣轉時說名有對？越彼於餘，此不轉故。或復礙者是和合義，謂眼等法於自境界及自所緣和合轉故。

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.