'Reverse' in the Bible

Behold, I have received mission to bless; and he hath blessed, and I cannot reverse it.

and said, If it please the king and if I have found grace before him, and the thing seem right to the king, and I be pleasing in his sight, let it be written to reverse the letters devised by Haman the son of Hammedatha the Agagite, which he wrote to destroy the Jews that are in all the king's provinces.