Normally, it is incorporated provisions during setting sale property promises that sometimes recognizing them is the origin of some differences among the contract parties and courts. Considering the fact that nowadays the main part of exchanges are occurred as credit, the seller of commodities suspend the termination of exchange with failure to pay the price in the text of contraction and or in its description section in order to escaping from the long process of trial and the enforcement of sentences. It is commonly interpreted as the termination spontaneous bets of the contract. There are doubts and criticisms about the nature and validity of such term. Regarding to that in jurisprudence writings and the legal works, it has not surveyed the nature of discussed assumption and drawbacks on it so much, in the present article while substantive reviewing of the above mentioned bets and responding to the criticisms said and comparing it with the similar institutions, its justification has been accepted in the form of pending the outcome of bets.