Revelation 18:19

And they cast dust... — Comp. Ezekiel 27:30. The casting of dust or earth on the head is a token of sorrow and humiliation; it bears relation to the sitting in the dust. The one upon whom the sorrow had fallen sat in the dust or ashes. The attitude expressed that he had been brought very low, even to the ground. The mourning friends who came round him cast dust on their heads to express that they shared his sorrow. Thus it is related of Job: Job sat in the ashes (Job 2:8); the friends who came to comfort him sprinkled dust upon their heads towards heaven (Revelation 18:12). So in this place, Babylon has been brought low (comp. Isaiah 47:1); the mourners, whose gains sink with her fall, throw dust upon their heads.

(19) Alas! alas! that great city... — The lament is parallel with the laments of the kings and the merchants; the difference is the appropriate reference to the destruction of the shipping interests. Woe! woe! (or, Alas! alas!) the great city, in which all who had their vessels on the sea grew rich out of her costliness. By her “costliness” we are to understand her extravagances of living, and the splendour of her palaces which drew materials from all ports of the world. The lament ends with the repeated cry, “in one hour.” Because in one hour she was desolated.