When Sanballat the Horonite and Tobiah the Ammonite official heard about this, they were very much disturbed that someone had come to promote the welfare of the Israelites…But when Sanballat the Horonite, Tobiah the Ammonite official and Geshem the Arab heard about it, they mocked and ridiculed us. “What is this you are doing?” they asked. “Are you rebelling against the king?”

I answered them by saying, “The God of heaven will give us success. We his servants will start rebuilding, but as for you, you have no share in Jerusalem or any claim or historic right to it.” Nehemiah 2:10,19-20

            These individuals were not Jewish (Ammonite and Arabian) whose ancestors hated the Jews.  So there was a prejudice there that did not want to see the Jews rebuild into the great people they once were.  Plus, they probably had some power in this region and would lose that with Jews returning to the city.