He explained the beauty of the music to her but it was just casting pearls before swine.
他跟她讲解那音乐的美妙之处, 但这只不过是对牛弹琴而已。
She decided not to buy the most expensive wine for dinner, thinking that would be casting pearls before swine.
她决定宴请时不买最贵的酒，心想反正他们也不识货。
原声例句
VOA Special 2023年6月合集
The idiom " do not cast pearls before swine" means do not offer valuable things to people who will not appreciate them.
“不要把珍珠扔给猪”这句习语的意思是，不要把宝贵的东西送给不会欣赏的人。
英语百科
Pearls before swine
（重定向自Cast pearls before swine）
"Pearls before swine" and "casting pearls" refer to a quotation from Matthew 7:6 in Jesus's Sermon on the Mount: "Do not give what is holy to the dogs; nor cast your pearls before swine, lest they trample them under their feet, and turn and tear you in pieces."