成唯識論演祕 4.285

4.285

以有所緣與有境義而有別也。若有所緣，體唯能緣；若言有境，即通五根。要有所緣方有所依，故除根也。

Because possessing a cognitive object (ālambana) and possessing an objective realm (viṣaya) have different meanings. If it is 'possessing a cognitive object', its essence is exclusively the cognizing subject; if it is said to 'possess an objective realm', it applies generally to the five sense faculties. Only when it has a cognitive object does it have a basis; therefore the sense faculties are excluded.