Here [...] is the Homage to Fischer. Give it to Heine and tell him to look upon it as a letter to himself. He might preface the publication with a few words, explaining that this Homage, though intended to be made public, was originally a communication from the author to a mutual friend of Fischer. He should retain the date. Unfortunately I have been so much interrupted that I could not make the copy till to-day. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 445