What is the idiom that metaphor is extremely difficult to find?

Finding a needle in a haystack

dà hǎi lāo zhēn

[Definition] Finding a needle in a haystack. The scope of the metaphor is large; there are no clues; things are difficult to accomplish. Contains the meaning of wasted effort.

[Quotes] Wang Ming's "Chunwu Ji": "Ahem; it's just a low fate; bad people; looking for profit is like finding a needle in a haystack; looking for trouble is like dry sticks to light a fire."

< p> [Synonym] It is as difficult as climbing to the sky to catch the moon

[Antonym] It is as easy as flipping a hand, as easy as lifting a finger to catch it, and it is at your fingertips

[Usage] Often used in metaphorical sentences; it contains the meaning of helplessness. Generally used as object, attributive, and adverbial.

[Structure] More formal.

[Analysis] ~ Same as "fishing for the moon in the sea" and "fishing for the moon in the water"; both have the meaning of "wasting effort". But ~ although the goal is difficult to achieve, it is still possible to achieve it; "fishing for the moon in the sea" and "fishing for the moon in the water" are metaphors for not being able to achieve the goal no matter how hard we try; it is just a waste of effort.

[Example] Looking for someone in this deep mountain and dense forest; that’s it~.

Idioms have the following basic characteristics:

1. Structural fixity

The components and structural form of idioms are fixed and generally cannot be changed at will. Or add or subtract morphemes. For example, "the lips are dead and the teeth are cold" cannot be changed to "the lips are dead and the teeth are cold", "the lips are dead and the teeth are cold", "the lips are cold without teeth"; "the chest has no ink", nor can it be increased to "the chest has no ink". In addition, the word order in idioms is also fixed and cannot be changed at will. For example, "the ins and outs" cannot be changed to "the ins and outs of the situation," and "the great contributions" cannot be changed to "the great contributions."

2. Integrity of meaning

Idioms have integrity in meaning. "Its meaning is often not a simple sum of the meanings of its constituent components, but an overall meaning further summarized based on the meaning of its constituent components." 2 For example, "the fox fakes the tiger's power", the superficial meaning is "the fox fakes the tiger's power", The actual meaning is "relying on the power of others to oppress others"; "the rabbit dies and the dog is cooked", the superficial meaning is "when the rabbit dies, the hunting dog is cooked", but the actual meaning is "those who serve the ruler are abandoned after they are done." Or kill"; "forgetting to sleep and eat", the superficial meaning is "ignoring sleep and forgetting to eat", but the actual meaning is "extreme concentration and hard work" and so on.

3. Diversity of grammatical functions

From the perspective of Chinese grammar, Chinese idioms are equivalent to a phrase in a sentence, because a phrase can serve as different components in a sentence , so the grammatical functions of idioms are also diverse. Chinese idioms have various forms. As mentioned above, there are four-character idioms, five-character idioms, six-character idioms, seven-character idioms, eight-character idioms, etc. Among them, four-character idioms are the main form of Chinese idioms. Therefore, the analysis of the grammatical functions of idioms here mainly focuses on the analysis of four-character idioms serving as syntactic components.