promise (one) the earth(redirected from promise them the earth)
promise (one) the earth
To promise one something that is not feasible or cannot be done. Your clients will come to distrust you if you keep promising them the earth and then inevitably fail to deliver.
promise the earth
If someone promises the earth, they promise to give people things that they cannot in fact possibly give them. `Politicians have lost credibility,' he complained, `they promise the earth and don't deliver.'