Any easy way or background why Well + knife is Punishment? Knife is related punishment, but after killing with knife any history to through them in the well?
wikitionary details about 刑:
Originally written as 㓝, phono-semantic compound (形聲, OC *ɡeːŋ): phonetic 井 (OC *skeŋʔ) + semantic 刂. Later corrupted as ⿰幵刂, phono-semantic compound (形聲, OC *ɡeːŋ): phonetic 幵 (OC *kŋeːn) + semantic 刂.