isaiah 21:1 The burden of the desert of the sea. As whirlwinds in the south pass through; so it cometh from the desert, from a terrible land. - Free Bible Online

      Isa 21:1-10. REPETITION OF THE ASSURANCE GIVEN IN THE THIRTEENTH AND FOURTEENTH CHAPTERS TO THE JEWS ABOUT TO BE CAPTIVES IN BABYLON, THAT THEIR ENEMY SHOULD BE DESTROYED AND THEY BE DELIVERED.

      He does not narrate the event, but graphically supposes himself a watchman in Babylon, beholding the events as they pass.

      1. desert--the champaign between Babylon and Persia; it was once a desert, and it was to become so again.
      of the sea--The plain was covered with the water of the Euphrates like a "sea" (Jer 51:13, 36; so Isa 11:15, the Nile), until Semiramis raised great dams against it. Cyrus removed these dykes, and so converted the whole country again into a vast desert marsh.
      whirlwinds in the south-- (Job 37:9; Zec 9:14). The south wind comes upon Babylon from the deserts of Arabia, and its violence is the greater from its course being unbroken along the plain (Job 1:19).
      desert--the plain between Babylon and Persia.
      terrible land--Media; to guard against which was the object of Nitocris' great works [HERODOTUS, 1.185]. Compare as to "terrible" applied to a wilderness, as being full of unknown dangers, De 1:29.

JFB.