'Sign' in the Bible

even the censers of these sinners against their own lives; and let them be made beaten plates for a covering of the altar: for they offered them before Yahweh; therefore they are holy; and they shall be a sign to the children of Israel."

and the earth opened its mouth, and swallowed them up together with Korah, when that company died; what time the fire devoured two hundred fifty men, and they became a sign.