Daniel 6:8

6:8 Now let the king issue a written interdict so that it cannot be altered, according to the law of the Medes and Persians, which cannot be changed.

Daniel 6:13

6:13 Then they said to the king, “Daniel, who is one of the captives from Judah, pays no attention to you, O king, or to the edict that you issued. Three times daily he offers his prayer.”