Is it permissible in Islamic law for a Muslim to trade with the American government by purchasing goods online and reselling them to the government with a small profit margin, knowing that this transaction is legal and pre-approved, despite a delay of approximately one month in receiving payment?

The described scenario involves selling what one does not own, which is Islamically forbidden and prohibited, based on the Prophet's (peace and blessings be upon him) saying to Hakim bin Hizam: "Do not sell what you do not possess." The Islamic alternative is for the offerer to promise the customer to provide the goods and determine their price after acquiring ownership, and then the contract is concluded. Alternatively, he can act as a broker for the owner of the goods or for the buyer in exchange for a known commission or for whatever exceeds the specified price.