This is a cry of grief, not a request for an answer. The seafarers had grown rich through the city: "wherein were made rich all that had ships in the sea by reason of her costliness" (Revelation 18:19). Barnes reads their cry as, "What calamity has ever come upon a city like this?" Gill says the city was unmatched "as before for magnificence and grandeur, so now for sorrow, desolation, and ruin." Matthew Henry's Concise Commentary observes that their sorrow is "a mere worldly sorrow; they do not lament for the anger of God, but for the loss of outward comforts."

No one answers the mariners. They go on mourning: they "cast dust on their heads, and cried, weeping and wailing, saying, Alas, alas, that great city... for in one hour is she made desolate" (Revelation 18:19). Then a very different voice speaks: "Rejoice over her, thou heaven, and ye holy apostles and prophets; for God hath avenged you on her" (Revelation 18:20). A mighty angel throws a great millstone into the sea and says, "Thus with violence shall that great city Babylon be thrown down, and shall be found no more at all" (Revelation 18:21).

This lament echoes Ezekiel's lament over Tyre, the great sea-trading city. There the seafarers "cast up dust upon their heads" and cried, "What city is like Tyrus, like the destroyed in the midst of the sea?" (Ezekiel 27:30, 32). Gill points to the seafarers' lament over Tyre (Ezekiel 27:30) as the source of this and other expressions, and Barnes says the picture of the city's great merchants probably comes from the description of Tyre in Ezekiel 27. Throwing dust on the head was, in Barnes' words, "A common sign of lamentation and mourning among the Orientals" (Job 2:12). Barnes explains that "shipmaster" translates kubernetes, a governor, then the steersman or pilot of a ship (Acts 27:11).

Commentators differ on what Babylon stands for. Barnes and Gill read her as papal Rome, and Gill even reads the ships as dioceses and religious houses, and thinks the traders at sea "may design the pope's legates." The text itself calls her "that great city" (Revelation 18:10). The KJV prints this cry with an exclamation point; the ESV renders it as a question.

Revelation 18 lets the reader hear two responses to the same event. Those who grew rich from Babylon stand far away and grieve what they lost. Heaven is told to rejoice, because "God hath avenged you on her" (Revelation 18:20), and soon a great multitude says, "true and righteous are his judgments" (Revelation 19:1-2). The sailors' cry shows what they treasured. Matthew Henry notes that what grieved them was "not their sin, but their punishment."

Before the fall, God had called, "Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues" (Revelation 18:4). Her greatness was real, but her sins had "reached unto heaven" (Revelation 18:5). The question "What city is like unto this great city!" is answered by the millstone: she will be "found no more at all" (Revelation 18:21).