Jamieson, Fausset and Brown on Revelation 21:9

9. The same angel who had shown John Babylon the harlot, is appropriately employed to show him in contrast new Jerusalem, the Bride (Re 17:1-5). The angel so employed is the one that had the last seven plagues, to show that the ultimate blessedness of the Church is one end of the divine judgments on her foes.

unto me--A, B, and Vulgate omit.

the Lamb's wife--in contrast to her who sat on many waters (Re 17:1), (that is, intrigued with many peoples and nations of the world, instead of giving her undivided affections, as the Bride does, to the Lamb.