Hadith 3503
Narrated Hakim ibn Hizam: Hakim asked (the Prophet): Messenger of Allah, a man comes to me and wants me to sell him something which is not in my possession. Should I buy it for him from the market? He replied: Do not sell what you do not possess.
Hadith 3504
Narrated Amr bin Suhaib: On his father's authority, said that his grandfather Abdullah bin Amr reported the Messenger of Allah ﷺ as saying: The proviso of a loan combined with a sale is not allowable, nor two conditions relating to one transaction, nor profit arising from something which is not in one's charge, nor selling what is not in your possession.