to place righteousness before family (idiom); ready to punish one's own family if justice demands it
Definitions (粵典–words.hk)
動詞
為咗比親情更重大嘅道義，將親人或親屬消滅 to bring an end to a relative or close subordinate (e.g. executing, banishing, terminating, etc.), for justice or for a greater cause
Definitions (Wiktionary)
phrase, idiomatic
to place righteousness before family; to be ready to punish one's own family if justice demands it