A.T. Robertson Commentary Revelation 17:1

"And there came one of the seven angels that had the seven bowls, and spake with me, saying, Come hither, I will show thee the judgment of the great harlot that sitteth upon many waters;" — Revelation 17:1 (ASV)

I will show thee (δειξω σο). Future active of δεικνυμ. It is fitting that one of the seven angels that had the seven bowls should explain the judgment on Babylon (16:19) already pronounced (14:8). That is now done in chapters Re 17; 18.

The judgment of the great harlot (το κριμα της πορνης της μεγαλης). The word κριμα is the one used about the doom of Babylon in Jer 51:9. Already in 14:8 Babylon is called the harlot. Πορνης is the objective genitive, "the judgment on the great harlot."

That sitteth upon many waters (της καθημενης επ υδατων πολλων). Note triple use of the article της. In Jer 51:13 we have εφ' υδασ πολλοις (locative in place of genitive as here). Babylon got its wealth by means of the Euphrates and the numerous canals for irrigation. Rome does not have such a system of canals, but this item is taken and applied to the New Babylon in 17:15. Nahum (Nahum 3:4) calls Nineveh a harlot, as Isaiah (Isaiah 23:16f.) does Tyre.