E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Witham.
You were born, I suppose, at Little Witham. A reproof to a noodle. The pun, of course, is on little wit. Witham is in Lincolnshire.
1
I will be sworn she was not born at Wittham, for Gaffer Gibbs says she could not turn up a single lesson like a Christian.Sir Walter Scott Heart of Mid-Lothian, chap. xxxii.
Puns of this sort are very common. (See BEDFORDSHIRE, NOD, DUNCE, CRIPPLEGATE, SHANKS NAG, etc.)