So you shall appoint Aaron and his sons, and they shall observe and attend to their priesthood; but the layman (non-Levite) who approaches [the holy things] shall be put to death.”

Lo! they, became unto the sons of Israel, by the advice of Balaam, the cause of daring acts of treachery against Yahweh, over the affair of Peor, - and then came the plague against the assembly of Yahweh!