2 Samuel 21:5-6
5-6Then they told the king, "The man who tried to get rid of us, who schemed to wipe us off the map of Israel—well, let seven of his sons be handed over to us to be executed—hanged before God at Gibeah of Saul, the holy mountain."
And David agreed, "I'll hand them over to you."
7-9The king spared Mephibosheth son of Jonathan, the son of Saul, because of the promise David and Jonathan had spoken before God. But the king selected Armoni and Mephibosheth, the two sons that Rizpah daughter of Aiah had borne to Saul, plus the five sons that Saul's daughter Merab had borne to Adriel son of Barzillai the Meholathite. He turned them over to the Gibeonites who hanged them on the mountain before God—all seven died together. Harvest was just getting underway, the beginning of the barley harvest, when they were executed.