Doing a job before knowing about the price offered
Question

                What is the ruling if a person does a job, then finds out that the one who wanted it done said “Whoever does such and such will have such and such”?
Praise be to Allah. If he does it before finding out that the one who wanted it 
          done said “Whoever does such and such will have such and such” does 
          not deserve the price named. But it is good manners to give him something 
          that will please him, that is similar to or more than the price for 
          this work.