My wondrously bountiful friend,
Your never-ceasing benevolence imposes upon me the pleasant duty of sending you these few lines before I had originally intended to write, in order that I may make you a surprise. Since you wish it so, I am engaged for the first time in setting down in writing my plan for “Parzival”: although I have not once taken up the sources of this subject since the time of my earliest acquaintance with it and although, even now, I must avoid becoming involved in it, except in passing - as on this occasion - the subject - even given such self-command - has swollen in so rich and powerful a way that I cannot complete this elaboration of it in the two days that I had initially thought possible. I need a few more profitable mornings: the draft will then be finished, and he for whom it is uniquely intended shall then receive the work at once.
Source: Selected Letters of Richard Wagner, trans. and ed. Stewart Spencer and Barry Millington (W. W. Norton & Company, 1988), No. 332