惩前毖后 (懲前毖後) chéng qián bì hòu

chéng qián bì hòu set phrase to punish those before to prevent those after
Domain: Idiom 成语
Notes: (CC-CEDICT '懲前毖後'; Guoyu '懲前毖後'; Mathews 1931 '懲前毖後', p. 50)