E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Nid dune souris dans loreille dun chat. A mares nest. This French phrase is the translation of a line in Wynkyn de Wordes Amusing Questions, printed in English in 1511. Demand: What is that that never was and never will be? Response: A mouses nest in a cats ear. (See MARES NEST.)