摘要：这个成语源自《新约。马太福音》第7章:“Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them un
cast, throw, etc. pearls before swine
对牛弹琴；明珠暗投；
to give or offer valuable things to people who do not understand their value
If you say that someone is casting pearls before swine, you mean that they are wasting their time by offering something that is helpful or valuable to someone who does not appreciate or understand it.
在猪面前抛示珍珠，言下之意就是：把有价值的东西给不识货的人; 对牛弹琴
swine 是个旧词，书面词，即今为 pigs,不过 swine 单复同形。
这个成语源自《新约。马太福音》第7章:“Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you”.由于 to cast pearls before swine,
比喻确切形象生动,在后世不断引用中而成为一个固定成语：
You do not value what should be valued , I see I was casting pearls before swine.
你不重视应该重视的东西，我觉得我是在对牛弹琴。
He explained the beauty of the music to his wife but it was casting pearls before swine.
他跟他妻子讲解那音乐之美，可是这无异于对牛弹琴。
She read him Byron's poems, and it was casting pearls before swine.
她为他朗诵拜伦的诗，简直是对牛弹琴。
Trying to explain to them the importance of body language in communication is just like casting pearls before swine.
你给他们讲解人体语言在交际中的重要性简直是对牛弹琴。
She read them Shakespeare, but it was casting pearls before swine.
她为他们朗诵莎士比亚著作，但那等于对牛弹琴。
To explain to him is to cast pearls before swine.
跟他解释就等于对牛弹琴。
It's a waste of time to talk to her. She always turns a deaf ear to others. Don't cast pearls before swine.
劝她是浪费时间。她听不进去别人的话。别对牛弹琴了。
I won't waste good advice on John anymore because he never listens to it. I won't cast pearls before swine.
我再也不会把好建议浪费在约翰身上了，因为他从来不听。我不会再对牛弹琴。
Don't waste your time and breath. It's not worth casting pearls before swine.
不要浪费你的时间和精力。对牛弹琴是不值得的。
来源：翅膀英语
