Then it must have been said by Gandalf - he's the only one who would say those polite words!
On second thought, Gandalf is nowhere to be found in the minor works - let's see, a wizard? Oh, it's Artaxerxes, doing his magic on
Roverandom!
__________________
'Mercy!' cried Gandalf. 'If the giving of information is to be the cure of your inquisitiveness, I shall spend all the rest of my days in answering you. What more do you want to know?' 'The whole history of Middle-earth..
.'