'Statute Forever' in the Bible

And this is yours, the heave offering of their gift, with all the wave offerings of the sons of Israel. I have given them to you and to your sons and to your daughters with you, by a statute forever. Everyone that is clean in your house shall eat it.

But the Levites shall do the service of the tabernacle of the congregation, and they shall bear their iniquity, a statute forever throughout your generations, that among the sons of Israel they have no inheritance.

And he who gathers the ashes of the heifer shall wash his clothes and be unclean until the evening. And it shall be to the sons of Israel, and to the stranger that lives among them, for a statute forever.