成唯識論述記 7.723

7.723

述曰：此識因中有漏者，是俱生起，任運無力，必杖第八識以為外質，自方變故。既非業果體力，須藉質起。無漏位不定有，緣真如、虛空、去來，無外質故；緣現在世、有為法等，有外質故。

The Commentary states: When tainted in the causal stage, this consciousness is innately arisen; functioning spontaneously and lacking force, it must rely upon the eighth consciousness as an external archetype before it can transform on its own. Since it is not the substance of a karmic maturation, its power must depend on an archetype to arise. In the untainted stage, its presence is indefinite: when apprehending tathatā, space, and the past and future, it lacks an external archetype; when apprehending the present time, conditioned dharmas, and so forth, it possesses an external archetype.