If I had more time, I would have written a shorter letter

Variously attributed to Ben Franklin, Blaise Pascal, Robert Sayre, Mark Twain. Anyone know for sure who first said it

Thanks all

I thought it was about the speech given by Lincoln, known as the Gettysburg Address, wasn't it? ~ along the lines of "if you wanted a shorter speech I would have needed longer to prepare"...? But I probably misremember.

T.S. Eliot gets the credit, but there’s this telegram exchange:
NEED 2-PAGE SHORT STORY TWO DAYS.
Mark Twain replied:
NO CAN DO 2 PAGES TWO DAYS. CAN DO 30 PAGES 2 DAYS. NEED 30 DAYS TO DO 2 PAGES

Where you been, Dale? I must be a masochist; I've missed you.

Anna, I'm flattered