Cast pearls before swine

Cast pearls before swine

Meaning:

Offer or show something valuable, good, or beautiful to someone who does not understand its value

If you are casting pearls before swine, you are wasting your time showing or offering something very helpful or valuable to someone who does not understand or appreciate it.

Example:

Don't bother explaining Shakespeare to Bob. It would be like casting pearls before swine.

Tom wouldn't listen to Sarah's wise advice. She was just casting pearls before swine.