唯識二十論述記 2.99

2.99

述曰：以微所擬東、非東等，左手之東，即是西等。無此一分非是左手他不行處。以西即東故，樹東應至西故，二相擊定無相障，行者往也。應立量云：手相擊等應不相障；無方分故；如虛空等。此無方分亦不相障，故以為喻。《成唯識》說：「又若見、觸壁等物時，唯得此邊，不得彼分。既和合物即諸極微，故此極微必有方分。」

Commentary: Because the east faced by a paramāṇu is not east and so forth, the east of the left hand is precisely its west and so forth. There is no part that is not reached by the other, the left hand. Because west is precisely east, the east of a tree should reach the west; hence when two strike each other, there definitely would be no mutual obstruction. "To reach" (行) means to go. A formal inference should be formulated: "Hands striking each other or the like should not obstruct each other; because they lack spatial divisions; like empty space and the like." Here, lacking spatial divisions also entails not obstructing each other, hence it is used as an example. The Cheng weishi lun states: "Furthermore, when seeing or touching an object such as a wall, one perceives only this side and does not perceive that part. Since the aggregated entity is precisely the paramāṇus, these paramāṇus must have spatial divisions."