敲冰求火

Explanation: Knocking on the ice to find the fire. Analogy impossible things. 　　Usage: -Linked; as predicate, object; metaphor impossible things 　　Source: "Big bright Tripitaka," the next volume: "knock the ice to fire, on the power fail." Thesaurus:  seek a hare in a hen's nest, draw water with a bamboo basket; all in vain, ask the way from a blind person, Dao in the blind, Drilling the ice to fire, Making fire drill ice, Zuanhuodebing, Yuanshanqiuyu, Yuanmuxiyu Antonym Group:  very easily obtainable, acquire sth.easily, Hand to cite, be sure to succeed easily, as easy as taking sth. out of one's pocket, have full assurance to get go after an easy prey as one who catches a tuttle in a jar, go on [upon] the scamp