摩訶止觀 8.145

8.145

就今果報身上，復起善惡，習續習因、習果。總望前世，此習續是果；若望後世，此習續是因。數家明報得鴿雀身是報果，多婬是習果。論家，鴿身及多婬俱是報果，婬由貪起，貪是習果。又今生煩惱起，名「習因」；成業即「報因」。後生起煩惱，名「習果」；苦痛名「報果」。

With respect to the present body of retribution, wholesome and unwholesome [actions] arise anew, habituating and continuing the habituated causes and habituated effects. Looking back collectively at past lives, this habituated continuity is an effect; if looking toward future lives, this habituated continuity is a cause. The Abhidharma masters explain that receiving the body of a pigeon or a sparrow as retribution is a retribution effect, while frequent lust is a habituated effect. The Śāstra masters [hold that] the pigeon body and frequent lust are both retribution effects; lust arises due to greed, and greed is the habituated effect. Furthermore, when afflictions arise in the present life, they are called 'habituated causes'; when they constitute karma, they are 'retribution causes.' When afflictions arise in a future life, they are called 'habituated effects'; pain and suffering are called 'retribution effects.'