What are the controls that preserve the rights of both parties in installment sales and of society?

Selling on a known deferred payment basis is permissible, due to the generality of Allah's Almighty saying: "O you who have believed, when you contract a debt for a specified term, write it down." And an increase in price in exchange for deferment is not objectionable. It is important to note that it is not permissible for a Muslim to sell a commodity that is not in their possession and then go and buy it, nor to sell it while it is still at the seller's premises before taking possession of it, based on the Prophet's (peace be upon him) saying: "Do not sell what you do not possess" and "Whoever buys food should not sell it until he has taken full possession of it."