Esther 8:8

8:8 Now you write in the king’s name whatever in your opinion is appropriate concerning the Jews and seal it with the king’s signet ring. Any decree that is written in the king’s name and sealed with the king’s signet ring cannot be rescinded.

Daniel 6:8-15

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. 6:9 So King Darius issued the written interdict.

6:10 When Daniel realized that a written decree had been issued, he entered his home, where the windows in his upper room opened toward Jerusalem. Three times daily he was kneeling and offering prayers and thanks to his God just as he had been accustomed to do previously. 6:11 Then those officials who had gone to the king came by collusion and found Daniel praying and asking for help before his God. 6:12 So they approached the king and said to him, “Did you not issue an edict to the effect that for the next thirty days anyone who prays to any god or human other than to you, O king, would be thrown into a den of lions?” The king replied, “That is correct, according to the law of the Medes and Persians, which cannot be changed.” 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.”

6:14 When the king heard this, he was very upset and began thinking about how he might rescue Daniel. Until late afternoon he was struggling to find a way to rescue him. 6:15 Then those men came by collusion to the king and said to him, “Recall, O king, that it is a law of the Medes and Persians that no edict or decree that the king issues can be changed.”

Daniel 6:17

6:17 Then a stone was brought and placed over the opening to the den. The king sealed it with his signet ring and with those of his nobles so that nothing could be changed with regard to Daniel.