All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
Selling food coupon is an act that involves indecent Jahalaa' because the sold item is unknown as regards its type and quantity. Besides, whenever Jahalaa' exists, the sale contract is considered invalid, since the Prophet (PBUH) forbade sales in which Jahalaa' is involved as stated that Abu Hurairah (May Allah Be Pleased with him) narrated that: "The Messenger of Allah (PBUH) forbade Gharar transaction sand Hasah transactions."
Based on the above narration, food coupon is to be allocated to the needy by the party in charge for food delivery as an indication on their behalf of supporting the essential goods. Yet, selling them leads to exploiting the need of the poor, changes the genuine purpose for which they were distributed and turns this aid to a profitable business in favor of deep-pocketed persons.
Al-Imam Ibn Mailk as well stated in his book [Al-Moataa'] a narration in which it confirms that having profit out of poor's charity is impermissible, it reads as follow:" He (Al-Imam Malik) had heard that receipts were given to people in the time of Marwan Ibn Al-Hakam for the produce of the market at Al-Jar. People bought and sold the receipts among themselves before they took delivery of the goods. Zayd Thabit and one of the Companions of the Messenger of Allah (PBUH) went to Marwan Ibn Al-Hakam and said: "Marwan! Do you make usury halal?" He said: "I seek refuge with Allah! What is that?" He said: "These receipts which people buy and sell before they take delivery of the goods." Marwan therefore sent a guard to follow them and to take them from people's hands and return them to their owners.
Accordingly, selling food coupons earlier than owing the goods by whosoever is impermissible; however, if the eligible recipient received the intended goods in return of their due coupon, then he is permitted to sell them by any price he desires. And Allah Knows Best.