Cut off their hands ... - After they were dead. Their hands and feet were hung up in a place of public resort, both to deter others and also to let all Israel know that David was not privy to the murder of Ish-bosheth.
Related Commentaries of 2 Samuel 4:12
2 Samuel 4:12
12 And David commanded his young men, and they slew them, and cut off their hands and their feet, and hanged them up over the pool in Hebron. But they took the head of Ishbosheth, and buried it in the sepulchre of Abner in Hebron.