摩訶止觀 8.143

8.143

云何名「習因、習果」？阿毘曇人云：「習因是自分因，習果是依果。」又習名「習續」。自分種子相生，後念心起，習續於前；前念為因，後念為果。此義通三性。論家但在善惡，無記無習續也。

What are called "habitual cause" and "habitual fruit"? Abhidharma masters say: "A habitual cause is a cause of its own kind; a habitual fruit is a dependent fruit." Furthermore, habit means "habitual continuation." Seeds of one's own kind generate one another, so that when a subsequent thought-moment arises in the mind, it habitually continues the preceding one; the preceding thought-moment is the cause, and the subsequent thought-moment is the fruit. This meaning applies to all three natures [good, bad, and indeterminate]. Treatise masters restrict it to the good and bad; the indeterminate has no habitual continuation.