Isaiah 21 - The burden on Babylon, Dumah and Arabia

I) The command to go up against Babylon (1-5)

Babylon is called the Wilderness of the Sea because the nation has many lakes and marshes, so it was referred to as a “sea.”  A command is given to Elam and Media, referring to Persia (modern day Iran) to march against Babylon to "end the sighing" she has caused. (v2).  

Verses 3 to 5 seem to be the reaction of Isaiah who saw the vision of how his people were made slaves in Babylon with horror and trembling. He cried out desperately "Arise, O Princess; Oil the shield!" 

We know that the Persians conquered the Babylonian empire in 539 BC and let the first exilic Jews to return to Jerusalem in 538 BC, after 60 years in exile. 

II) The watchman and his mission (6-10)

The Lord told Isaiah to set up a symbolic watchman. This gave Isaiah confidence that this vision of the fall of Babylon will surely come. The watchman stands on his tower everyday to look for the good news, and then riders came to announce: "“Fallen, fallen is Babylon; and all the carved images of her gods he has shattered to the ground.” (v9)

A similar phrase is used in Revelation: "Another angel, a second, followed, saying, “Fallen, fallen is Babylon the great, she who made all nations drink the wine of the passion of her sexual immorality.” (Rev 14:8)  In Revelation, Babylon is used as a symbolic name for the world system, which is corrupted in sin.  Just like Babylon of old will be wiped out, this will be the eventual condition of the world system when Jesus comes again. We are asked to “Fear God and give him glory, because the hour of his judgment has come, and worship him who made heaven and earth, the sea and the springs of water" (Rev 14:7)

III) The burden of Edom (11-12)

Dumah is another name for Edom. Someone from Edom asked the watchman "what time of the night?" The night refers to the period of suffering.  The watchman answers "the morning comes and also the night", which may be saying that there will be a respite after the Assyrians but the night returns during the Babylon rule. The exact times or duration of the exile was not given to Isaiah. He ask the person in the vision to "inquire again", probably to a later prophet. 

Indeed, Jeremiah 25:12 prophesied: "Then after seventy years are completed, I will punish the king of Babylon and that nation, the land of the Chaldeans, for their iniquity, declares the LORD, making the land an everlasting waste."

IV) The burden upon Arabia (13-17)

Isaiah had a vision of the refugees from Arabia, hungry and thirsty. He calls out for people to provide food and water to the refugees. All this will be from the Assyrian invasion, which will happen within a year from Isaiah's writing.