Adam Clarke on Judges 3:13

The city of palm trees - This the Targum renders the city of Jericho; but Jericho had been destroyed by Joshua, and certainly was not rebuilt till the reign of Ahab, long after this, 1Kgs 16:34. However, as Jericho is expressly called the city of palm trees, Deu 34:3, the city in question must have been in the vicinity or plain of Jericho, and the king of Moab had seized it as a frontier town contiguous to his own estates. Calmet supposes that the city of palm trees means En-gaddi.