Pearls before Swine

New to me this week … the expression usually expressed in the negative proverbial form - 'don't cast your pearls before swine', and is found in the Bible, Matthew 7:6, first appearing in English bibles in Tyndale's Bible, 1526:

The biblical text is generally interpreted to be a warning by Jesus to his followers that they should not offer biblical doctrine to those who were unable to value and appreciate it.

In other words, to offer something valuable or good to someone who does not know its value i.e. I'm afraid you're casting pearls before swine with your good advice - she just won't listen.