3-5. GESENIUS, MAURER, &c., regard these verses as an address of the fugitive Moabites to the Jews for protection; they translate Isa 16:4, "Let mine outcasts of Moab dwell with thee, Judah"; the protection will be refused by the Jews, for the pride of Moab (Isa 16:6). VITRINGA makes it an additional advice to Moab, besides paying tribute. Give shelter to the Jewish outcasts who take refuge in thy land (Isa 16:3, 4); so "mercy" will be shown thee in turn by whatever king sits on the "throne" of "David" (Isa 16:5). Isaiah foresees that Moab will be too proud to pay the tribute, or conciliate Judah by sheltering its outcasts (Isa 16:6); therefore judgment shall be executed. However, as Moab just before is represented as itself an outcast in Idumea, it seems incongruous that it should be called on to shelter Jewish outcasts. So that it seems rather to foretell the ruined state of Moab when its people should beg the Jews for shelter, but be refused for their pride.
      make . . . shadow as . . . night . . . in . . . noonday--emblem of a thick shelter from the glaring noonday heat (Isa 4:6; 25:4; 32:2).
      bewray . . . wandereth--Betray not the fugitive to his pursuer.

JFB.