大方廣圓覺修多羅了義經略疏 1.811

1.811

四正勤者，四念處火，若得勤風則無所不燒，故次辦之。精進為體故總名勤，異外道勤故名為正。雖是一勤，隨義分四：一未生之惡遏令不生；二已生之惡斷令不續；三未生善令生；四已生善令廣。

The four right exertions: As for the fire of the four applications of mindfulness, if it catches the wind of diligence, there is nothing it does not burn; therefore they are elucidated next. With diligence as substance, they are collectively termed 'exertion'; because they differ from the exertion of non-Buddhists, they are termed 'right.' Although it is a single diligence, according to meaning it is divided into four: first, restraining unarisen evil so that it does not arise; second, severing already-arisen evil so that it does not continue; third, causing unarisen good to arise; fourth, causing already-arisen good to increase.