成唯識論述記 3.594

3.594

述曰：此意即是依此識故，施設三界、五趣、四生，是引果故。識是界、趣、生之本也，下自當知。言施設者，安立異名，識若斷滅，非界、趣、生，故此恒言正遮於斷，即重顯上一類義也。若善、染等體非一類，趣生應雜，許雜起故。由此識是一類無記，不可雜起。

The Commentary states: The meaning here is that relying upon this consciousness, the three realms, five destinies, and four modes of birth are posited, because it is the projected result. Consciousness is the root of the realms, destinies, and modes of birth, as will be understood below. The word "positing" is another name for establishment; if consciousness were cut off, there would be no realms, destinies, or modes of birth. Therefore, this word "constantly" directly excludes discontinuity; that is, it reiterates the meaning of "uniform" above. If wholesome, defiled, and so on were not uniform in substance, the destinies and modes of birth would be intermingled, because they would be permitted to arise intermittently. Because of this, consciousness is uniformly indeterminate and cannot arise intermittently.