A phrase can be used so frequently in a novel that quoting it becomes a coded signal you’re a fan of the book. The best example is ‘So it goes’ from SH5. It’s a motto, a tattoo, a stand alone Reddit post comment. For those who can’t place the quote it also serves as a cultural shibboleth.
But the only other ones I can think of are ’Es muss sein’ from TULoB and ‘Oh my valves!’ from CoD. (Why are all three words?!) But there must be others. I don’t mean famous one liners, I’m talking about multiple uses of a phrase. Can anyone mention another?
“Fear is the mind-killer…” from the Dune series.
“No great loss.” from The Stand, which IIRC King uses in conjunction with “So it goes” at least once, but don’t quote me on that.
“Ka is a wheel.” Another King quote, Dark Tower series
“God is Change.” Octavia Butler, Parable duology
Wasn’t “so it goes” one of Vonnegut’s favorite phrases to use too?