2 Samuel 21:8-9

8So the king took Armoni and Mephibosheth, the two sons of Aiah’s daughter Rizpah whom she had born to Saul, and the five sons of Saul’s daughter Merab whom she had born to Adriel the son of Barzillai the Meholathite.

9He turned them over to the Gibeonites, and they executed them on a hill before the Lord. The seven of them died together; they were put to death during harvest time – during the first days of the beginning of the barley harvest.