E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Dont you wish you may get it, Mrs. Crump? Grose says Mrs. Crump, a farmers wife, was invited to dine with Lady Coventry, who was very deaf. Mrs. Crump wanted some beer, but, awed by the purple and plush, said, in a half-whisper, I wish I had some beer, now. Mr. Flunkey, conscious that his mistress could not hear, replied in the same aside, Dont you wish you may get it? At this the farmers wife rose from table and helped herself. Lady Coventry, of course, demanded the reason, and the anecdote soon became a standing joke.