The source is 5,000 ans d'humeur juifs.
Here's a good short joke:
A man approaches a Rabbi.
'I know an old widow who's too poor to pay her rent. Can the community help?'
'Of course, here, take this. But tell me, are you family?'
'No Rabbi, I'm her landlord.'
Here's another:
WWII has been over for some years. An unemployed French man without visible means spends conspicuous amounts of money in bars and clubs by night and by day cruises around in his sports car.
'What's your secret?' his best friend asks him. 'Are you in the black market?'
'No, don't tell anyone, I'm hiding two jews in my cellar. They're paying me well.'
'But the war finished years ago!'
'Yes, but I haven't told them yet.'
Vir ad rabinum accedit.
"Scio viduam veterem quae nimis pauper est ad mercedem solvendum. Potestne communitas adiuvare?"
"Accipe hoc. Sed dic mihi, esne de familia eius?"
"Minime, rabbi, ego sum dominus eius."
Secundum bellum mundanum iam aliquot annos finitum est. Francogallus inexercitatus sine manifestis mediis noctu in tabernis et ganeis magnas pecunias expendit et interdiu in autocineto ludicro circumvehitur.
"Quod est arcanum tuum?" amicus eius quaerit. „Esne n foro nigro?"
"Minime, nemini dixerim, sed duos Iudaeos in cellario meo celo qui bene mihi solvunt."
"Sed bellum iam abhinc annos confectum est!"
"Verum est, sed nondum illis indicavi."