俱舍論疏 16.9

16.9

論「此黑白名至互相違故」，釋雜名也。言「黑白」者，就相續立，非一業亦黑亦白，非異熟亦可意亦不可意。善、惡，可意、不可意，互相違故。然由相續與黑雜故，即欲界業名為黑白。

The Śāstra says: "This designation 'dark and bright' […] because they mutually contradict"—this explains the name 'mixed'. The phrase "dark and bright" is established with respect to a continuity; it is not that a single karma is both dark and bright, nor that a maturation is both agreeable and disagreeable, because wholesome and unwholesome, agreeable and disagreeable, mutually contradict each other. However, because within a continuity it is mixed with the dark, karma of the desire realm is called dark and bright.