俱舍論疏 7.126

7.126

論「勢力劣故至加行善心」，答也。明三心不生加行善也。一勢力劣故，總三心也。二非作功用所引發故，異熟心也。三樂作功用，引發工巧、威儀轉故。後二心也。四總結也。

The Śāstra says, "Because their power is inferior ... preparatory wholesome mind": this is the answer. It explains that the three minds do not produce the preparatory wholesome. First, "because their power is inferior" covers all three minds generally. Second, "because it is not induced by making effort" refers to the mind of fruition. Third, "because the operation of craft and deportment is induced by taking pleasure in making effort" refers to the latter two minds. Fourth is the general conclusion.