成唯識論述記 1.100

1.100

第三，三者雖無文說，准諸經論判此有三：初二十五頌明唯識境；次有四頌明唯識行；末後一頌明唯識果。先觀所知，方起勝行。因行既備，果德乃圓，故為三也。此皆准釋《瑜伽》、《攝論》，故有此判。

Regarding the third threefold division: although it is not stated explicitly in the text, in accordance with the sūtras and treatises it is judged to have three parts: The first twenty-five verses explain the objects of consciousness-only; next are four verses explaining the practice of consciousness-only; the final single verse explains the fruit of consciousness-only. One first contemplates the knowable, and only then gives rise to superior practice. When the causal practice is complete, the virtues of the fruit are perfected; therefore it is divided into three. All these follow the explanations in the Yogācārabhūmi and the Mahāyānasaṃgraha, hence this division.