NEH 13:2

2 The reason for that was that the people of Ammon and the people of Moab did not give/sell any food or water to the Israelis [while the Israelis were going through their areas after they left Egypt]. Instead, the people of Ammon and Moab paid money to Balaam in order that he would curse the Israelis. But God commanded Balaam to bless the people, not to curse them.