cat in the sack

[anatgilady]

Hello,
I am looking for the idiom that describes a case where you buy something and cannot be sure you are not being fooled. In my language we use the phrase - "a cat in the sack". Any ideas? thank you

[Humble]

Hi, A,
You seem to know Russian. In English it's a pig in a poke.

Regards

[BobK]

.... and don't be confused by 'poke' - it's an old (now obsolete) noun meaning bag, related to the word 'pouch'.

b