Revelation 17:5-7 New Revised Standard Version (NRSV)
5 and on her forehead was written a name, a mystery: “Babylon the great, mother of whores and of earth’s abominations.” 6 And I saw that the woman was drunk with the blood of the saints and the blood of the witnesses to Jesus.
When I saw her, I was greatly amazed. 7 But the angel said to me, “Why are you so amazed? I will tell you the mystery of the woman, and of the beast with seven heads and ten horns that carries her.