瑜伽論記 5.497

5.497

心者通八識，無量差別自體展轉者謂三性四差別而轉，及因展轉者，謂前前心為因生後後自體心故，或心種子及餘緣能生心體皆名因展轉，前際叵知故名遠行。

'Mind' applies generally to the eight consciousnesses. 'Innumerable distinctions of own-nature in mutual succession' means operating through the four distinctions of the three natures; and 'mutual succession of causes' means because preceding minds serve as causes giving rise to subsequent own-nature minds, or mind-seeds and other conditions able to produce the substance of mind are all called mutual succession of causes. Because its anterior limit is impossible to know, it is called 'far-faring'.