What does Isaiah 15:2 mean?

This oracle against Moab is describing the response to a terrible judgment that will fall on the nation. Isaiah wrote that because two of the major cities have been destroyed, including the capital, Moab is defeated (Isaiah 15:1). The judgment has apparently taken the form of invading armies with Assyria as the most likely attacker.

Now, the prophet begins to record the response of the people of Moab, describing them as "he." This follows the common biblical practice of referring to a nation through its primary founder (Isaiah 27:6; Obadiah 1:6) The people have gone up to the temple and to Dibon, a major city just north of the Arnon River. They also have gone to the high places used for worship. In fact, these spots may all have been in or near the city of Dibon. This city was the center of the worship of the false Moabite god Chemosh. The people weep before this idol despite his inability to save them from destruction.

In addition, Isaiah reports that the people will go to Nebo and to Medeba to wail and mourn. Mount Nebo is a high mountain at the north end of the Dead Sea. The city of Nebo may have been nearby, and likely was destroyed as well. Medeba is a city just south of Heshbon, over the border in the territory of Ammon. Medeba, too, may have been wiped out.

The nation will enter an official state of mourning. The men all shave their heads bald and shave off their beards. The normal appearance for men at the time was an unshaved head, though perhaps cut short, and a long beard. Only in a times of official grief and mourning would all the men shave off their beards and hair together.