It's a secret ex-librarian's trick. If I told you I'd have to kill you except, being Mudcat, I wouldn't know where to find you, so you are safe.

Use quotation marks around a phrase to only search for those words in that order:

"Oh that the peats would cut themselves"

The trick can backfire a little bit if the words have been incorrectly remembered but if I don't get a good result with one line or phrase I'll usually try a different line.