attract flies with ice—it is impossible ? 以貍致鼠，～，雖工不能。(《呂氏春秋·功名》) You’ll work in vain if you try to get rid of the rats with foxes or attract flies with ice.
以冰致蠅yǐ bīnɡ zhì yínɡ
致：招引。用冰來(lái)招引蒼蠅。比喻不可能實(shí)現(xiàn)的事情。sheer impossibility, it is impossible