Abu Karayb, Muhammad bin al-'Ala' محمد بن العلاء - أبو كريب · The Book of Financial Transactions

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.

"The Messenger of Allah said: 'Wrongdoing is when a rich man takes a long time to repay a debt, and if one of you is referred to a rich man (to help repay debt), he should accept that referral."'