俱舍論疏 15.37

15.37

論「言屠羊者至當知亦爾」，重釋也。為活命故，要期盡壽恒欲害羊，名屠羊者。餘典刑等，亦要期盡壽恒有害意，名典刑者。

The treatise says: "The expression 'butcher of sheep'... should be known to be likewise."
This is a re-explanation. Because of making a livelihood, making a commitment for the rest of their life to constantly desire to harm sheep is called being a butcher of sheep. Other [occupations, such as] executioners, also make a commitment for the rest of their life to constantly have an intention to harm; hence they are called executioners.