The Messenger of Allah ﷺ said, "It is not permissible to combine a loan with a sale, nor to make two conditions in one sale, nor to profit from what you do not guarantee, nor to sell what you do not possess."
حدثنا زهير بن حرب حدثنا إسمعيل عن أيوب حدثني عمرو بن شعيب حدثني أبي عن أبيه حتى ذكر
قال رسول الله ﷺ لا يحل سلف وبيع ولا شرطان في بيع ولا ربح ما لم تضمن ولا بيع ما ليس عندك
[Sahih] Reported by Tirmidhi, Buyu, chapter on the dislike of selling what one does not possess, hadith no. 1234, and Ibn Majah, hadith no. 2188, from the hadith of Ismail, and Nasai, hadith no. 4615, from the hadith of Ayub, through him. Tirmidhi said, "hasan sahih," and Ibn Jarud graded it sahih, hadith no. 601, as did Hakim, 2/17, and Dhahabi agreed with him.