Bible Verses About Decrees: Of the Medes, irrevocable

Then the king, when he heard these words, was very displeased, and set his heart on Daniel to deliver him; and he labored until the going down of the sun to rescue him.

Then these men assembled together to the king, and said to the king, Know, O king, that it is a law of the Medes and Persians, that no decree nor statute which the king establishes may be changed.