'Stone' in the Bible

Then he went to his father’s house at Ophrah and murdered his brothers the sons of Jerubbaal, seventy men, [in a public execution] on one stone. But Jotham the youngest son of Jerubbaal was left alive, because he had hidden himself.

but you have risen against my father’s house today and have murdered his sons, seventy men, on one stone, and have made Abimelech, son of his maidservant, king over the people of Shechem, because he is your relative—