15 Then these men assembled unto the king, and said unto the king, Know, O king, that the law of the Medes and Persians is, That no decree nor statute which the king establishes may be changed.
Daniel 6:15 Cross References - KJ2000
Esther 8:8
8 Write you also for the Jews, as it pleases you, in the king's name, and seal it with the king's ring: for the writing which is written in the king's name, and sealed with the king's ring, may no man reverse.
Psalms 94:20-21
Daniel 6:8
8 Now, O king, establish the decree, and sign the writing, that it be not changed, according to the law of the Medes and Persians, which alters not.
Daniel 6:12
12 Then they came near, and spoke before the king concerning the king's decree; have you not signed a decree, that every man that shall ask a petition of any god or man within thirty days, except of you, 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 alters not.