Daniel 6:6-9

Then these commissioners and satraps agreed to approach the king and said to him, “King Darius, live forever! All the commissioners of the kingdom, the prefects and the satraps, the counselors and the governors have consulted and agreed together that the king should establish a royal statute and enforce an injunction that anyone who petitions (prays to) any god or man besides you, O king, during the next thirty days, shall be thrown into the den of lions. Now, O king, establish the injunction and sign the document so that it may not be changed, in accordance with the law of the Medes and Persians, which [insures that it] may not be altered or revoked.” So King Darius signed the document, that is, the injunction.