The next thing to saying a good thing yourself, is to quote one.

This sentence has no known source in Emerson's works, but its general sense does closely match the tenor of Emerson's essay "Quotation and Originality", in particular the sentence "Next to the originator of a good sentence is the first quoter of it." (listed above).

Gow, Foundations for Human Engineering (1931) contains the following passage: "I have the backing of Emerson, for it was he, I believe, who said that the next thing to saying a good thing yourself, if to quote one". It is not clear whether Gow is purporting to quote Emerson verbatim, or merely to paraphrase his work.