這個成語來字《舊約。申命記》第32章“耶和華遇見他在曠野荒涼、野獸吼叫之地，就環(huán)繞他，看顧他，保護他如同保護眼里的瞳人。”在圣經其他地方也有類似的話。英文版《舊約。詩篇》第17章有這樣的句子： Keep me as the apple of the eye,hide me under the shadow of the wings
成語the apple of one's eye是固定結構，不得寫成the apple of the eye of…的形式;在搭配上，它常與動詞be，keep,care for等連用。按其想象意義，它與漢語成語“掌上明珠”頗相似，但其比喻的對象較漢語“掌珠”更廣，因“掌珠”通常指心愛的女兒，而不能用與其他場合。
eg:Little Mary is the apple of her father's eye
Mind the reputation of your school as you care for the apple of your eye.
18.The writing/Finger on the Wall不詳之兆;大禍臨頭
這個成語的字面意思是“墻上的文字(或手指)”，而實際含義是a sign or warning of impending disaster(迫在眉睫的兇兆);a sign that sth bad will happen; a feeling that ones number is up;等等。其語言外殼與內涵是怎樣聯系起來的呢?
據《舊約。但以理書》第5章記述：有一次古巴比倫的國王伯沙撒正在宮殿里設宴縱飲時，突然，不知從哪里出現了一個神秘的手指，當者國王的面，在王宮與燈臺相對的粉墻上寫西了四個奇怪的單詞：MENE(彌尼)、MENE(彌尼)、TEKEL(提客勒)、UPHARSING (烏法珥新)。國王張皇失措，驚恐萬分，誰也不懂墻上所寫的字是什么意思。后來叫來了被虜的猶太預言家但以理，才明白了這幾個字的意思就是大難臨頭。他說：“彌尼就是上帝已經數算你國的年日到此為完畢;提客勒就是你被稱在天平里顯出你的虧欠;烏法珥新就是你的國分裂，歸與瑪代人和波斯人。”果然，當夜伯沙撒被殺，又62歲的瑪代人大利烏取而代之。
依次，“墻上的文字(或手指)”就表示身死國亡的兇兆。英語中這個成語有幾種表達方式：the writing/handwriting on the wall或a finger on the wall,通常與be，like等系動詞連用;有時寫成see/read the writing on he wall的句型，表示提出警告,such as :Don't you see the writing on the wall, 有時候也可省略on the wall，只說Don't you see the writing?意思也是一樣的。
eg:This inexplicable incident seemed,like the Babylonian finger on the wall,to be spelling out the letter of my judgement...
In this house of his there was writing on every wall.His business-like temperament protested against a mysterious warning that she was not made for him.
John's emplyer had less and less work for him;John could read the writing on the wall.
The writing on the wall is clear:if man behaves like an animal and allow hs population to increase while each nation steadily increases he coplexity and range of its environment,nature will take her course and the law of the Jungle will prevail.
When Bill's team lost four games in a row,he saw the handwriting on the wall.
19.Not an iota of沒有一點點，絲毫也不
iota是希臘字母表中第9個字母“I”的名稱。not an iota of 出自《新約。馬太福音》第5章：“律法的一點一畫都不能廢去，都要成全。”因為iota是希臘字母表中最小的一個字母，它有時可以寫作一短橫置于其他字母之上;遺漏這一點點對發(fā)音并無什么影響，只按規(guī)則不能減少而已�！陡Ｒ魰匪f的律法，系指“摩西律”，意即無論何人都不允許隨便廢去這戒律哪怕是最小的一條，甚至其中的一個字母，一個小小短橫也不得更動或遺漏。
由此，在語言中遺留下來這個成語，轉義表示not a bit of ;not one jot or little;not at all等意思。iota在這里，相當于漢語“小不點兒”的意思。
Eg:Science deals with things in a practical way.Science means honest,solid knowledge,allowing not an iota of falsehood,and it involves herculean efforts and gruelling toil.
There is not an iota of truth in the story.
20.The Salt of the Earth社會中堅;民族精華;優(yōu)秀份子
The Salt of the Earth這個成語，字面意思“世上的鹽”
鹽是飲食中不可缺少的調味品，人體若缺鹽，健康就會受到影響，出現種種疾病。鹽還有殺菌、解毒、消炎、除污等多種功用，它既是“百藥之王”，又是工業(yè)之母，確是值得珍視的東西。在許多民族的習俗匯總，鹽被當作敬客的高貴禮品。
The Salt of the Earth一詞出自《圣經》，據《新約。馬太福音》(Matthew)第5長記載：耶穌對他的門徒說: Ye are the salt of the earth:but if the salt have lost his savor,wherewith shall it be salted? 在這里，salt用于轉義，表示flavor;of the earth即of the world。這是耶穌登山垂訓論 福 ，所講福音結尾的話，他把門徒比做“世上的鹽”，這是極高的稱贊。這句話在后世不斷引用變成了一個典故性成語，轉義為the most valuable members of sociey;the finest type of humanity;a person or a group of people having the best character 之意
eg: He does a lot of good jobs and is considered to be the salt of the world.
You all are the salt of the earth.Our hope is placed on you
21.Cast pearls before swine對牛彈琴;白費好意
To Cast pearls before swine的意思是“珍珠頭在豬玀前面”。
swine是個舊詞，書面詞，即今為pigs,不過swine單復同行，本句為復數。
這個成語源自《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國際性成語，常用來表示to offer sth valuable or beautiful 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，這個成語與漢語成語“明珠按投”相似，但是寓意不同，基本上不對應;按一比喻意義，它相當于“對牛彈琴”，“向驢說經”“一番好意給狗吃”“狗咬呂洞賓，不識好人心”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
22.a wolf in sheep's clothing批著羊皮的狼;貌善心惡的人
耶穌在加利利一帶傳道布教，收了很多信徒。有一天，他對門徒說: Beware of false prophets,which come to you in sheep's clothing,but inwardly they are ravening wolves
eg:Mrs.Martin trusted the lawyer until she realized that he was a wolf in sheep's clothing
One who teaches morality and practises immorality is a wolf in lamb's skine
23.separate the sheep from the goats區(qū)別好壞，分清良莠
《新約。馬太福音》記述：“And before him shall be gathered all nations:and he shall separate them one from another,as a shepherd divideth his sheep from the goats”
由于《圣經》的影響，sheep和goat在英語中的形象截然不同，前者比喻好人，后者比喻壞人。英語中有關goat的成語，大多貶義。如：to play the goat=play the fool(瞎胡鬧);to get sb's goat(觸動肝火) ;等等。《圣經》說牧羊人要分辨綿羊和山羊，“把綿羊安置右邊，山羊左邊”。據說野山羊�；爝M羊群里，引誘綿羊，故牧養(yǎng)人必須把它們區(qū)分開來，以免混淆。
由此，人們用to separate the sheep from the goats這個成語，來比喻to separate the good from the wicked; to divide good or useful people from bad or useless
eg:We'll go through the list of members,and separate the sheep from the goats
Have faith in me,please.I can separate the sheep from the goats
