Originally posted by cheshirecatstevensDon't look a gift horse in the mouth
I was told not to look in his mouth, but i coudn't resist. And to tell you the truth I don't get what the big fuss is all about. Teeth and a toung!
Big effin deal, regular horses have them too I suspect.
Meaning
Don't be ungrateful when you receive a gift.
Origin
This comes into the category of phrases called proverbs, that is, 'short and expressive sayings, in common use, which are recognized as conveying some accepted truth or useful advice'.
As horses age their teeth begin to project further forward each year and so their age can be estimated by checking how prominent the teeth are. This incidentally is also the source of another teeth/age related phrase - long in the tooth.
The advice given in the 'don't look...' proverb is: when given a present, be grateful for your good fortune and don't look for more by examining it to assess its value.