'Reverse' in the Bible

Behold, I have received a command to bless. He has blessed, and I can't reverse it.

She said, "If it pleases the king, and if I have found favor in his sight, and the thing seem right to the king, and I am pleasing in his eyes, let it be written to reverse the letters devised by Haman, the son of Hammedatha the Agagite, which he wrote to destroy the Jews who are in all the king's provinces.