Ruling on selling a commodity before taking possession of it

Question:
What is the ruling on the following: A person selects the car he wants, and the merchant, for example, buys it for twenty thousand riyals and sells it to the one who selected it for twenty-five thousand riyals in installments, with a guarantee or a guarantor who is in debt, and the car is registered in the buyer's name from the beginning to the end?

Answer:
It is obligatory that he first buys it on the seller's account. Once he takes possession of it and holds it in his name, and the procedures for the sale and purchase are completed, then he may sell it to whoever he wishes to sell it to. Everyone is free of obligation until the first sale is completed, the first buyer takes possession of it, it is registered in his name, and the matter is concluded. Then it is sold to the second interested party.
As for using stratagems with other things to buy it before the first purchase of it is completed, this is an error. It is necessary that the first seller bought it on his account, took ownership of it on his account, and took possession of it, and then he sells it afterwards. Likewise, the buyer does not sell it until he has also taken possession of it, taken control of it, and held it.
And you heard in the seminar about a matter that was not pointed out, which is the issue of salam. The doctor ... pointed it out. Salam is a sufficient alternative, if it is facilitated—people know it well—it would suffice them from the promise (wa'd), and it would suffice them from many other things.
And salam, as you heard, is that one buys from the liability of a person a known item. One buys from his liability a known amount of wheat, or rice, or a described car, for a known term, with money paid in advance that this seller needs. So he says: I sell you from my liability, for example, one thousand sa' of wheat, or one thousand kilograms of wheat, or one thousand kilograms of rice, for a certain amount of money paid in advance. This is called salam.
Or I sell you a car of such a model, with such a description, after one year, or after two years, with capital paid in advance, which is the price paid immediately. This is called salam, and the scholars have established its permissibility.
And the Prophet (peace and blessings be upon him) said, when he arrived in Madinah and they were making forward purchases in fruits for one year and two years, he said—(peace and blessings be upon him): Agreed upon by al-Bukhari and Muslim.
So this salam is also a sufficient alternative to tawarruq sales, and it is a sufficient alternative to many other things in which a person may become entangled, such as a loan from which his partner may bestow favor upon him, or he may come to it while being in need of it. This is a sale in which there is no favor to anyone, a known sale for a known term, in which the capital is paid in advance.