Respectfully Quoted: A Dictionary of Quotations. 1989.
Moncure Daniel Conway (18321907)
There is a tradition that, on his return from France, Jefferson called Washington to account at the breakfast-table for having agreed to a second chamber. Why, asked Washington, did you pour that coffee into your saucer? To cool it, quoth Jefferson. Even so, said Washington, we pour legislation into the senatorial saucer to cool it.
MONCURE D. CONWAY, Omitted Chapters of History Disclosed in the Life and Papers of Edmund Randolph, p. 91 (1888). This story is probably apocryphal.