Is it leagal to sell your home before the sell date give by the mortgage lender attorney?

Please be more clear, I would assume the closing date given by the mortgage company will specify the proper payoff for the mortgage as of that date? I am merely guessing since you are not clear as to who is it being sold to, back to the mortgage company? Is it set for foreclosure but you are selling it befire it does?? Please give a more complete idea of what you are talking about