Cast, throw, etc. pearls before swine
Definition 1 of 1
Pro Tip 1/3Biblical Origin
The phrase originates from the Bible, implying sacredness given to undeserving individuals without appreciation. 
His in-depth knowledge of poetry was cast before swine at the rowdy party.
Pro Tip 2/3Metaphorical Use
Used metaphorically to suggest wasted efforts in sharing something with those incapable of appreciating it. 
Explaining the intricacies of chess to someone who hates board games is like throwing pearls before swine.
Pro Tip 3/3Negative Connotation
Conveys a negative judgment about the recipient's inability to appreciate the value being offered. 
Presenting complex math to first graders could be seen as casting pearls before swine.