the Messenger of Allah prohibited lending on the condition of a sale, or to have two conditions in one transaction, or to profit from what you do not posses.
Sunan an-Nasa'i Book 44, Hadith 181
← Previous Hadith "The Messenger of Allah was wearing two Qitri garments which, if he sat and sweated, would become heavy (and uncomfortable). A Jewish man got some fabric from Ash-sham so I said: 'Why don't you send word to him to buy two garments from him, and pay him when things get easier?' So he sent word to him, but he said: 'I know what Muhammad wants; he wants to go away with my money and take them (the two garments).' The Messenger of Allah said; 'He is lying; he knows that I am one of the ones who fear Allah the most, and are most honest in fulfilling trusts.

Sunan an-Nasa'i Book 44, Hadith 180 Next Hadith → "My father told me, mar rating from his father, from his father (and he mentioned 'Abdullah bin 'Amr) that he said: "The Messenger of Allah said: "It is not permissible to lend on the condition of a sale, or to stipulate two conditions in one transaction, or to make a profit on that which you do not possess.

Sunan an-Nasa'i Book 44, Hadith 182