2 Samuel 21:6-8

let seven men [chosen] from his sons (descendants) be given to us and we will hang them before the LORD [that is, put them on display, impaled with broken legs and arms] in Gibeah of Saul, the chosen one of the LORD.” And the king said, “I will give them.” But the king spared Mephibosheth the son of Jonathan, the son of Saul, because of the LORD’S oath that was between David and Saul’s son Jonathan. So the king took the two sons of Rizpah the daughter of Aiah, whom she bore to Saul, Armoni and Mephibosheth, and the five sons of Merab the daughter of Saul, whom she had borne to Adriel the son of Barzillai the Meholathite.