俱舍論記 15.55

15.55

「四由所因善根斷故」者，戒本由善根得，今善根斷，故捨彼戒。故《正理》云「四由斷滅所因善根，謂表、無表業等起心斷故。」

Regarding the passage "Fourth, through the severance of the roots of good from which it originates": morality was originally obtained from roots of good; now that the roots of good are severed, that morality is therefore abandoned. Thus the Nyāyānusāra states: "Fourth, through the eradication of the roots of good from which it originates; that is, because the mind that originates manifest and non-manifest karma is severed."