A Pig in a Poke
A Pig in a Poke : Phrases
An offering or deal that is foolishly accepted without being examined first.
'Don't buy a pig in a poke' might seem odd and archaic language. It's true that the phrase is very old, but actually it can be taken quite literally and remains good advice.
The advice being given is 'don't buy a pig until you have seen it'. This is enshrined in British commercial law as 'caveat emptor' - Latin for 'let the buyer beware'. This remains the guiding principle of commerce in many countries and, in essence, supports the view that if you buy something you take responsibility to make sure it is what you intended to buy.
A poke is a small sack or bag and is the origin of the word pocket. The word is still in use in several English-speaking countries, notably Scotland and USA. A poke is just the sort of bag that would be useful for carrying a piglet to market.
A pig that's in a poke may turn out to be no pig at all. If a merchant tried to cheat by substituting a lower value animal, the trick could be uncovered by letting the cat out of the bag. The advice has stood the test of time and people have been repeating it for getting on for five hundred years, maybe longer. Fraser's Magazine (1858) reprinted a piece from Richard Hill's (or Hilles') Common-place Book, 1530, which gave this advice to market traders:
"When ye proffer the pigge open the poke."