The waters which you saw, where the harlot sits
Having described the mystery of the beast with the seven heads and ten horns, the angel now tells John the mystery of the woman (Rev. Rev. 17:7+). Earlier, the angel identified the woman as the great harlot who sits on many waters (Rev. Rev. 17:1+). See commentary on Revelation 17:1. See The Great Harlot. These same waters form the sea out of which the first Beast arose (Rev. Rev. 13:1+). See commentary on Revelation 13:1.
are peoples, multitudes, nations, and tongues
The common fourfold designation within the book of Revelation denoting a worldwide population (Rev. Rev. 7:9+). In some instances, tribes or kings appears for multitudes (Rev. Rev. 5:9+; Rev. 10:11+; Rev. 11:9+; Rev. 14:6+). See Four: the Entire World, the Earth. These are the peoples, nations, tongues, and kings about which John was told he must prophesy (Rev. Rev. 10:11+). He is now fulfilling that assignment. Although the woman is said to be a city (Rev. Rev. 17:18+), her influenceand possibly her supportis global in scope. Her influence was scattered worldwide with the introduction of languages in the judgment of Babel when all mankind dispersed from a central location having already imbibed of her corrupting wine (Gen. Gen. 11:9). We believe she spans both geography and history, for the Beast with seven heads is empowered by the dragon (Rev. Rev. 13:1+ cf. Rev. Rev. 12:3+) who is Satan and assumed dominion over the world as early as the Fall of Adam and Eve (Mtt. Mat. 4:8; Luke Luke 4:6; John John 12:31; John 14:30; 2Cor. 2Cor. 4:4; 1Jn. 1Jn. 5:19). If the seven heads represent seven world kingdoms of special significance in the plan of God, then the womans global influence extends from the earliest of those empires through the time of the Second Coming of Christ and the establishment of the Millennial Kingdom. See #4 - Seven Heads/Kings. See Babylon of Old.