Okay, so everybody knows that Gandalf says: "I did not pass through fire and shadow to bandy crude words with a witless worm," or something like that. When he's talking to Grima Wormtongue.
Well, in that weird Peter O'Toole movie, The Ruling Class (1972), the 'Electric Messiah' says this:
"I've not travelled 20 million miles through galactic space to bandy words with a poxy moon loony who thinks he's me!"
Okay,
A couple possibilities suggest themselves. Philippa Boyens or Fran Walsh or Peter Jackson or whoever may have seen The Ruling Class at some point (seems likely, given their off-color taste), and internalized the unforgettable structure and cadence of this line. Perhaps unconsciously. Much as George Harrison internalized "He's So Fine" without realizing it.
Or: they were both drawing on the same unknown earlier source, much like the Gospel writers and Q.
If anybody knows the answer, please write to me in the comments section.