From Longman Dictionary of Contemporary Englishthe impossiblethe impossiblesomething that cannot be doneattempt/do/ask etc the impossible I just want to be able to buy healthy food at a reasonable price. Is that asking the impossible? → impossible
Examples from the Corpus
attempt/do/ask etc the impossible• We can not expect teachers to do the impossible.• He would attempt the impossible and set up an airline from scratch in three months. 