Is it permissible to exchange subsidized food commodities for unsubsidized, free-market commodities or for a sum of money, and is it permissible for the merchant to dispose of the subsidized food commodities left with him?

These matters are based on the state's condition regarding the disposal of these materials. It appears that the state does not permit the disposal of these materials. If the beneficiary does not need them, it is not permissible for him to relinquish his right to them for compensation from the shop owner or anyone else. This is a circumvention that must be stopped unless the responsible authority approves. If the state permits it, there is no harm in exchanging one bottle of oil for two bottles if the type of oil differs, such as olive oil and sesame oil, as each has its own ruling. However, if the type is the same, then it is not permissible to have a differential exchange, as that would be usury (riba).