What is the ruling on purchasing a government food card designated for the poor for less than its real value, and then obtaining a larger sum of money in the bank account, and should this transaction be stopped?

Selling government-subsidized food vouchers by the poor before receiving the food is forbidden (haram), and this practice must be stopped. However, after the food has been received, there is no harm in buying it from them. If the poor person does not give anything in exchange for the voucher, then selling the food before it is received is permissible.