'Perpetual Statute' in the Bible

The priestly sons of Aaron, moreover, shall blow the trumpets; and this shall be for you a perpetual statute throughout your generations.

As for the assembly, there shall be one statute for you and for the alien who sojourns with you, a perpetual statute throughout your generations; as you are, so shall the alien be before the Lord.

Only the Levites shall perform the service of the tent of meeting, and they shall bear their iniquity; it shall be a perpetual statute throughout your generations, and among the sons of Israel they shall have no inheritance.

The one who gathers the ashes of the heifer shall wash his clothes and be unclean until evening; and it shall be a perpetual statute to the sons of Israel and to the alien who sojourns among them.

So it shall be a perpetual statute for them. And he who sprinkles the water for impurity shall wash his clothes, and he who touches the water for impurity shall be unclean until evening.