Analysis of the necessity of cash price in forward sale transactions

The common idea among the Imamiyeh jurists is that the price should be paid in contract meeting in a way that one of the conditions of the forward sale contracts is regarded as the necessity to submit the price in the meeting. It is not clear however that is this condition necessary to follow for the consolidation of the contract without which no ownership is determined? As it is the case in exchange of money، or the ownership is transferred to the buyer even before submitting the price. Although jurists have not explicitly discussed، asked or replied the above mentioned questions، they have implied to them. The traditions received around this subject are not capable of proving this condition، nor is there a general principle to refer to because with other proofs، there is no room for referring to the principle. Maybe the most important proof here is the consensus of the jurists which is undermined by many questions. An important point to notice is that to prove the necessity of this condition in such transactions many jurists have resorted to the invalidity of transacting debt with debt while the same jurists have referred to the necessity of the cash price in forward sale transactions to prove the invalidity of transacting debt with debt which will lead to the vicious circle. Considering above mentioned problems it is possible to omit this condition from the requirements of the validity of forward sale transactions.