(Devarim 19:1) "When the L-rd your G-d cuts off the nations whose land the L-rd your G-d gives to you": in your merit.
"and you inherit them and you dwell in their cities and in their houses": Because it is written "and you inherit them and you dwell in their cities," I might think that you are not permitted to add (to the existing settlement); it is, therefore, written (Ibid. 12:29) "and you dwell in their land" — Wherever you wish to build, build.