Cast pearls before swine對(duì)牛彈琴；白費(fèi)好意
To Cast pearls before swine的意思是“珍珠頭在豬玀前面”。swine是個(gè)舊詞，書(shū)面詞，即今為pigs,不過(guò)swine單復(fù)同行，本句為復(fù)數(shù)
這個(gè)成語(yǔ)源自《新約。馬太福音》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 efore swine,比喻確切，在后世不斷引用中而成為一個(gè)國(guó)際性成語(yǔ)，常用來(lái)表示to offer sth valuable or dbeautiful to those who can't appreciate it;to give what is precious to those who are unable to understand its value等意思，含有輕蔑嘲笑色彩。按其字面意義，這個(gè)成語(yǔ)與漢語(yǔ)成語(yǔ)“明珠按投”相似，但是寓意不同，基本上不對(duì)應(yīng)；按一比喻意義，它相當(dāng)于“對(duì)牛彈琴”，“向驢說(shuō)經(jīng)”“一番好意給狗吃”“狗咬呂洞賓，不識(shí)好人心”等
She read them Shakespeare,but it was casting pearls before swine
I won't waste good advice on John any more because he never listens to it.I won't cast pearls before swine
...and when I let the upper floor to Cap'en Cuttle,oh i do a thankless thing,and cast pearls before swine
To Cast pearls before swine的意思是“珍珠頭在豬玀前面”。swine是個(gè)舊詞，書(shū)面詞，即今為pigs,不過(guò)swine單復(fù)同行，本句為復(fù)數(shù)
這個(gè)成語(yǔ)源自《新約。馬太福音》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 efore swine,比喻確切，在后世不斷引用中而成為一個(gè)國(guó)際性成語(yǔ)，常用來(lái)表示to offer sth valuable or dbeautiful to those who can't appreciate it;to give what is precious to those who are unable to understand its value等意思，含有輕蔑嘲笑色彩。按其字面意義，這個(gè)成語(yǔ)與漢語(yǔ)成語(yǔ)“明珠按投”相似，但是寓意不同，基本上不對(duì)應(yīng)；按一比喻意義，它相當(dāng)于“對(duì)牛彈琴”，“向驢說(shuō)經(jīng)”“一番好意給狗吃”“狗咬呂洞賓，不識(shí)好人心”等
She read them Shakespeare,but it was casting pearls before swine
I won't waste good advice on John any more because he never listens to it.I won't cast pearls before swine
...and when I let the upper floor to Cap'en Cuttle,oh i do a thankless thing,and cast pearls before swine
