'Stone' in the Bible

Then he went to his father’s house at Ophrah and killed his brothers the sons of Jerubbaal, seventy men, on one stone. But Jotham the youngest son of Jerubbaal was left, for he hid himself.

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

Out of all these people 700 choice men were left-handed; each one could sling a stone at a hair and not miss.