you buy a car from a car agency, receive it and then sell it to another person for an instant or a deferred payment, there is no harm in that. However, if you buy that person the car before buying it or after buying it but before receiving it, this is not permissible. The Prophet (peace be upon him) said,
"Do not sell what you do not possess."
(Related by the Five Compilers of Hadith (Imams Ahmad, Abu Dawud, Al-Tirmidhy, Al-Nasa'y and Ibn Majah) on the authority of
Hakim ibn Hizam) It was also related by
Ibn Hibban in his Sahih book of authentic Hadith.
Al-Tirmidhy said, "This Hadith is Hasan (good) and Sahih (authentic)."
It is related in the same chapter from
`Amr ibn Shu`ayb from his father from his grandfather in the Hadith books of
Abu Dawud and
Al-Tirmidhy, and is considered Sahih (authentic) by
Ibn Majah, that the Messenger of Allah (peace be upon him) said,
“A loan and a sale are not lawful (together), or two conditions in a sale (two transactions combined in one), or to make a gain of something that is not delivered to you, or to sell what you do not possess.”
The phrase "what you do not possess" means what is not in one's possession. And this answers the two points of the question. (Part No. 13; Page No. 237)
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.