Origin of phrase "Done and done"

[fighting_ignorant]

Where does that phrase come from? When did it originate? It’s obviously difficult to google the answer to this one, hope some dedicated linguo-doper can dredge up the goods here.

[Kat]

Well, I did find this page which discusses the origin, theorizing it to be an 18th century Irish expression.

it seems that the usual convention was that a bet was agreed on the mere word of the two principals if both said “done”… Hence “done and done” meant that a binding agreement had been mutually accepted.