唯識二十論述記 1.25

1.25

二者、安立大乘中所說三界唯識理。諸宗說有心外境故，不信三界唯心之理，故今成也。今言「大乘三界唯識」，即顯所詮唯識之理。

Second, it establishes the principle that the three realms are vijñapti-mātra as taught in the Mahāyāna. Because the various schools assert that there are objects external to the mind, they do not believe the principle that the three realms are mind-only; hence it is now established. The present statement that 'the three realms in the Mahāyāna are vijñapti-mātra' thus reveals the principle of vijñapti-mātra that is expressed.