In Reply to: You don't know from where you speak posted by Brian on October 14, 2009 at 15:54:
: I have heard an old English expression a couple of times, but can't find it now doing any kind of search. It is: "you don't know from where you speak". Any clues?
I suspect you may be thinking of "You know not whereof you speak", which is just an archaic way of saying "You don't know what you're talking about". (VSD)