Ibn Ezra on Exodus 21:25/אבן עזרא על שמות כ״א:כ״ה

1BURN. Keviyyah (bum) is to be taken at face value; that is, it refers to a burn caused by fire.

2Some say that petza (wound) refers to a bleeding wound and chabburah (stripe) to a blow that does not draw blood. However, the Gaon says that petza refers to breaking a bone and chabburah to a bleeding wound.