Quotes Uncovered: Honest Abe

Photo: The Library of Congress

I’m back to inviting readers to submit quotations whose origins they want me to try to trace, using my book, The Yale Book of Quotations, and my more recent research.
Hugo asked:

“Better to remain silent and be thought a fool than to speak out and remove all doubt.” – Abe Lincoln

The Yale Book of Quotations has the following entry:

“Better to remain silent and be thought a fool than to speak out and remove all doubt.”
Attributed to Abraham Lincoln in Golden Book, Nov. 1931. The Chicago Daily Tribune, May 10, 1923, printed, “It is better to remain silent and be thought a fool, than to talk and remove all doubts,” as a submission by reader Benedict J. Goltra.

Matt Woodley asked:

In my line of work (I help pastors develop sermons) I hear the following statement attributed to St. Francis of Assisi: “Preach the Gospel at all times–and if necessary, use words.” Apparently he never said it.

Right. Can any of our researcher/readers track down the earliest findable appearance of this apocryphal quotation?
As always: do any readers have any other quotations whose origins they would like me to attempt to trace?