俱舍論記 23.58

23.58

「若得頂法至不斷善根」者，釋第二句。若得頂法，雖復有退造無間業墮惡趣，於前煖法更增畢竟不斷善根。又《正理》云「若得頂已不斷善根，如何經說天授退頂？由彼曾起近頂善根，依未得退密作是說。」

"If one attains the dharma of summits ... does not sever the roots of good": this explains the second line. If one attains the dharma of summits, even though there may still be regression, committing deeds of immediate retribution, and falling into the bad destinies, compared to the previous heat one further gains the quality of never ultimately severing the roots of good. Furthermore, the *Nyāyānusāra* says: "If having attained summits one does not sever the roots of good, why does the sūtra state that Devadatta regressed from the summits? Because he had previously given rise to roots of good close to the summits, this was said with implicit reference to his regression before reaching attainment."