idiom : common saying : a two-part allegorical saying > to touch somebody's tender spot
Contents
Play the snake hit seven inches
  Explanation: Metaphor to speak must seize the major aspects of work.
  Usage: Complex sentence; as the predicate clause; metaphor grasp the main aspects of speech act
  Source: Qing Wu Jingzi "Scholars" 14 back: "I only wish to have nothing to do, end up 'the water did not wash the boat,' but things have to 'hit the snake hit seven inches' was wonderful."
  Examples: But things have "~" only wonderful, and your husband on your CD. (Qing Wu Jingzi "Scholars" Fourteenth back)
No. 2
  I also only willing to get nothing, ended up "water does not wash boat" but things have to "fight to fight twenty-inch snake" was wonderful. - "The Scholars"
Translated by Google
Grasp the key metaphor to work, it is easy victory
  Grasp the key metaphor to work, it is easy victory. Qing Wang Youguang "Wu playing together under the saying snake playing in the seven-inch": "Snake has seven inches below the head, abdomen above, watch for so clear, hit too heavy, the system of its Achilles heel, was the carry on ... ... Although saying this is really combine Military Machine. "" The Scholars "14th back:" I only wish things were not to end up 'the water did not wash boat,' but things have to 'beat the snake to play seven inches' was wonderful . "" red flags were fluttering on her own factory guerilla ":" Zhang, deputy director of health made a specific arrangement: 'play snake Yaoda seven inches, eyebrows and beard can not be grabbed ... ...' "
Translated by Google
No. 4
  词 目 打蛇打七寸
  发 音 dǎ shé dǎ qī cùn
  释 义 比喻说话做事必须抓住主要环节。
  示 例 但做事也要“~”才妙,你先生请上裁。(清·吴敬梓《儒林外史》第十四回)
  为什么打蛇要打“七寸”
  打蛇就要命中要害。俗话说“打蛇打七寸”,然而也有些人说“打蛇打三寸”的。尽管说法不太相同,但是这里却有一个相同点就是打蛇要打蛇的致命的地方。
  每当动物的脊椎骨受到重伤的时候,为脊椎骨所保护着的脊髓也便会受到重的伤害,神经的中枢与身体的其它部分的信道就会被阻碍。伤害越接近头部,影响力也就会越大。如果你打到它的尾巴,则对它的生命就没有影响。
  也许有的人会问:“那就干脆说“打脊椎骨”不就行了啦!为什么还要有“三寸”、“七寸 ”的说法呢?因为“三寸”的地方脊椎骨被打伤以及打断,它便无法抬起头来咬你;而“七寸”是它心脏的所在处,一受到致命的重伤,自然必死无疑。当然了,这“三寸”、“七寸”也并不是每一条蛇都相同的,因为蛇的种类与大小都有所不同。 
  其实"七寸"指的是一个笼统的部位,其实就是蛇的心脏部位,要是蛇不到七寸,你就照着蛇的腹部打(蛇和人不一样,心脏在腹部)!蛇头后的颈部的地方只是蛇的三寸,打了以后蛇只会昏死一段时间,不是真的死.因为打了三寸后蛇头部会马上缺血,所以会暂时昏死一段时间,但不是很长,所以最好打蛇的腹部!
English Expression
  1. v.:   touch somebody's tender spot,   hit somebody where it hurts
Thesaurus
We must remember, Qinzeiqinwang