瑜伽論記 3.177

3.177

彼唯是不斷因故等者，不正思惟與無明作不斷因不能作雜染因，體非染故，何者不起非理作意而有緣起，故名不斷因非雜染因。

To "that is solely a cause of non-interruption," and so on: Improper reflection serves as a cause of non-interruption for ignorance, but cannot serve as a cause of defilement, because its essence is not defiled. What [state] does not give rise to improper attention yet possesses dependent origination? Therefore, it is called a cause of non-interruption, not a cause of defilement.