<P> The expression uses the word "done" in the sense of "finished" or "settled", a usage which dates back to the first half of the 15th century . </P> <P> It usually means something along the line of: the consequence of a situation (which was once within your control), is now out of your control, that is, "there's no changing the past, so learn from it and move on ." </P> <P> One of the first - recorded uses of this phrase was by the character Lady Macbeth in Act 3, Scene 2 of the tragedy play Macbeth (early 17th century), by the English playwright William Shakespeare, who said: "Things without all remedy Should be without regard: what's done, is done" and "Give me your hand . What's done cannot be undone .--To bed, to bed, to bed!" </P> <P> Shakespeare did not coin the phrase; it is actually a derivative of the early 14th - century French proverb: Mez quant ja est la chose fecte, ne peut pas bien estre desfecte, which is translated into English as "But when a thing is already done, it cannot be undone". </P>

Who said what is done cannot be undone