Daniel 6:12 GW

[12] Then they went and spoke to the king about his decree. They asked, "Didn't you sign a decree which stated that for 30 days whoever asks for anything from any god or person except you, Your Majesty, will be thrown into a lions' den?" The king answered, "That's true. According to the law of the Medes and Persians the decree can't be repealed."