Codlin's your Friend, not Short
(Dickens: Old Curiosity Shop, chap. xix.). Codlin had a shrewd suspicion that little Nell and her grandfather had absconded, and that a reward would be offered for their discovery. So he tried to bespeak the goodwill of the little girl in the hope of making something of it.
“None of the speakers has much to say in actual hostility to Lord Salisbury's speech, but they all harp upon the theory that Codlin is the friend, not Short.” —Newspaper paragraph, Oct. 13th, 1885.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894