This was a very fine puzzle, and very satisfying. What I like with Sabre is that although you often have to work hard for the clues -- and sometimes it takes me quite a while to figure out each clue even *after* I have the correct answer... -- once you do figure it out you can be absolutely sure you have the right answer!
I do agree though that the phrase was VERY hard to find from scant clues. I'm not sure what could have been done to make that slightly more tractable. People have mentioned ODQ -- but when I assembled my letter pairs, I found one distinctive word (which turned out to be the first of the four words), but that word does NOT link to the relevant quotation in my (1996) edition of ODQ, though it seems like it really should so maybe that was a glitch that was fixed in later editions :-/ I didn't recognise the words, but the next thing I built from my letter pairs was an unlikely-looking bunch of possibilities one of which caused Google to spring into life (it turned out to be the second of the four words). And suddenly all became clear. But without Google I'd never have got there. The vague link in one clue is hardly an additional hint -- jeg's hint was better! although in my case I only understood even that AFTER I'd solved it all... :-)
Many thanks Sabre! Now, a nice numeric to take away on holiday with me...!