Prior to his departure, his patron Ferdinand von Waldstein writes to him:
Dear Beethoven! You are going to Vienna in fulfilment of your long-standing wishes. The genius of Mozart is mourning and weeping over the death of his pupil. He has found a refuge but no occupation with the inexhaustible Haydn ( … ) With the help of assiduous labour you shall receive Mozart’s spirit out of the hands of Haydn. Your true friend, Waldstein.
OT | Bonn d 29t. Oct. 792.
Ferdinand von Waldstein