Pearls Before Swine
Definition: something valuable presented to one who does not or will not recognize its worth
This is a Biblical reference, from Matthew 7:6:
Do not give dogs what is sacred; do not throw your pearls to pigs. If you do, they may trample them under their feet, and turn and tear you to pieces.
Why I Looked It Up
In a book about World War 1, a Captain was discussing some Christmas gifts provided to men at the Western Front:
[the area was] littered with lumps of plum pudding simply chucked away. It’s pearls before swine to try to treat some men as human beings.