In Agatha Christie's book The Listerdale Mystery, in the story Swan Song, there is the following qoute:
It required no imagination to realise that his father's name had been Cohen.
This comes after a description of Mr Cowen, the agent of an Opera Singer.
The description is:
He was a tall man, clean-shaven, with a frame rather too well covered, and clothes that were rather too faultless. His hair was very black and shining, and his teeth were aggressively white. When he spoke he had a way of slurring his 's's' which was not quite a lisp, but came perilously near to it.
Why is it then relatively obvious (i.e. it requires no imagination) that Mr Cowen's actual surname is Cohen?