'According to the Law' in the Bible

Now, O king, establish the interdict, and sign the writing, that it be not changed, according to the law of the Medes and Persians, which altereth not.

Then they came near, and spake before the king concerning the king's interdict: Hast thou not signed an interdict, that every man that shall make petition unto any god or man within thirty days, save unto thee, O king, shall be cast into the den of lions? The king answered and said, The thing is true, according to the law of the Medes and Persians, which altereth not.