“…prayers ought to be brief, frequent, and intense. For God does not ask how much and how long you have prayed, but how good the prayer is and whether it proceeds from the heart.
Therefore Christ says now: “Your heavenly Father knows what you need before you ask for it.” It is as if He would say: “What are you up to? Do you suppose that you will talk Him down with your long babbling and make Him give you what you need? There is no need for you to persuade Him with your words or to give Him detailed instructions; for He knows beforehand what you need, even better than you do yourself.” If you came before a prince or a judge who knew your case better than you could describe it to him and tried to give him a long-winded account of it, he would have a perfect right to laugh at you or, more likely, to become displeased with you. Indeed, as St. Paul says (Rom. 8:26), “We do not know how we are to pray.” Therefore when He hears us, whatever He gives us is something in excess of our understanding or our hopes. Sometimes He lets us go on asking for something which He does not give right away, or perhaps does not give at all, knowing very well what is necessary and useful for us and what is not. We ourselves do not see this, but finally we have to admit that it would not have been good for us if He had done His giving on the basis of our petition. Therefore we must not go into a long harangue to give Him instructions or prescriptions about what He should do for us and how He should do it. He intends to give in such a way that His name might be hallowed, His kingdom extended, and His will advanced.”
— Martin Luther, vol. 21, Luther’s Works, Vol. 21  : The Sermon on the Mount and the Magnificat, ed. Jaroslav Jan Pelikan, Hilton C. Oswald and Helmut T. Lehmann, Luther’s Works, Mt 6:14 (Saint Louis: Concordia Publishing House, 1999, c1956). page 143