2 Samuel 4:6

And they came thither into the midst of the house, as though they would have fetched wheat; and they smote him under the fifth rib: and Rechab and Baanah his brother escaped.

Cross-reference

In 2 Samuel 2:23, Abner strikes Asahel in the belly with a spear — the same fatal wound inflicted on Ish-bosheth here.

In 2 Samuel 3:27, Joab kills Abner by stabbing him in the stomach — identical method to the assassination of Ish-bosheth here.

In 2 Samuel 20:10, Joab kills Amasa with a belly strike — the same method used against Ish-bosheth here.