'Sign' in the Bible

The censers of these {who have sinned} at the cost of their lives, let them be made into gilded leafing plating for the altar; because they presented them {before Yahweh}, they are holy; and they will be a sign for the {Israelites}.'"

And Yahweh said to Moses, "Bring back the staff of Aaron before the testimony as a guard and sign for the children of rebellion, and let them finish their grumblings before me and not die."

and the land opened its mouth and swallowed them with Korah, when that company died, when the fire consumed two hundred and fifty men, and they were a sign.