[...] Please let me know briefly, but by return, whether you have time to do the pianoforte arrangement from The Rhinegold quickly and promptly? If you can, I will send you the score at once, with part of The Valkyrie score at the same time. The reason why I cannot send you the latter quite complete is that I have been constantly ill for the last two months and actually bedridden most of the time; I have had to give up work entirely all the while. You can judge accordingly how good-humoured I feel. I had to put off Liszt who was to visit me now, and I expect him in the spring.—[...]
Source: Letters of Richard Wagner, Vol. 1, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 294