Allow me, my dear brother, I know that you know that usury is not permissible, and there are types of usury. In your explanation, you talked about a commodity, which is a car, but in the case of the currency market, it is money just like gold.

Whoever says the future is forbidden, you should judge this example before prohibiting or permitting.
Ali
He owns a car dealership. The price of each car is 10 thousand dollars.
Ahmad
He does not own a car dealership and understands this field well, and he only has 2000 dollars, and this amount does not allow him to own a dealership. He wants to work in this field because he excels at it...

Ahmad decided to go to Ali and contract with him to buy the car valued at 10 thousand dollars and give Ali the 2000 dollars, and the car remains with Ali until Ahmad returns and pays him the remaining amount of 8000 dollars.