1 Thessalonians 5:21 Law of the Land

Law of the Land or Law of the Case? When Blackstone, and Jefferson by reference, said "...no human laws should be suffered to contradict these" they intended what they wrote. I can think of no better Maxim^. [I don't know if this is a Maxim].

If this [Maxim] is violated isn't separation of powers violated in US and State Constitutions?