Daniel 6:10 (KJV)

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 altereth not.

Wherefore king Darius signed the writing and the decree.

Now when Daniel knew that the writing was signed, he went into his house; and his windows being open in his chamber toward Jerusalem, he kneeled upon his knees three times a day, and prayed, and gave thanks before his God, as he did aforetime.

Then these men assembled, and found Daniel praying and making supplication before his God.

Then they came near, and spake before the king concerning the king’s decree; Hast thou not signed a decree, that every man that shall ask a petition of any God or man within thirty days, save of 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.