Dearest Richard,
When I saw the Grand Duke last night for the first time after his return, he told me much about the visit you paid him at Lucerne. I do not know what impression your acquaintance with him has left on you, as we have had no news from you for such a long time, but from what I have heard, and what has already happened, I conclude with tolerable certainty that we shall see you here for the first performance of Tristan, AT THE LATEST. May God grant that it will be sooner; and I need not tell you that nothing I can do will be left undone. Dingelstedt will shortly write to you about Rienzi, which is to be performed next season, in December or January. Last winter we were unable to get on with the work for reasons which, as they exist no longer, are not sufficiently important to be discussed. Let me soon hear from you.
Franz Liszt
Source: Project Gutenberg eBook #4234, Correspondence of Wagner and Liszt — Volume 2, No. 261