At work we discussing a project that we would design and then turn it over to another owner. My boss said that wouldn’t work because the other owner wouldn’t want a project that we had designed. That would be like buying a pig in a poke, he said.
I knew what he meant, but wondered what a “poke” was and what that referred to. According to Wikipedia and a few other sources, a poke is a bag. At markets people would sell a young (live) pig and put it in a burlap bag for the customer to carry home. But shady vendors would substitute some other, cheaper animal instead of a valuable baby pig. One animal they might use would be a cat. That way the buyer would know something was alive, but then end up with nothing of value.
So that’s kind of funny that you actually want a pig in a poke and would get stuck with a cat. But the other neat part is that if you investigated the contents before handing over your money, then you “let the cat out of the bag” and realized the vendor was trying to cheat you.
I guess it was so widespread that it spawned two different phrases that are still in use hundreds of years later. Some scam!