Maliks Muwatta Book 32, Hadith Number 4.
Malik said, “When a man owes money to another man and he asks him to let it stay with him as a quirad, that is disapproved of until the creditor receives his property. Then he can make it a qirad loan or keep it. That is because the debtor may be in a tight situation, and want to delay it to increase it for him.”
Malik spoke about an investor who made a qirad loan to a man, and some of the principal was lost before he used it, and then he used it and made a profit. The agent wanted to make the principal the remainder of the money after what was lost from it. Malik said, “His statement is not accepted, and the principal is made up to its original amount from his profit. Then they divide what remains after the principal has been repaid according to the conditions of the qirad.”
Malik said, “Qirad loan is only good in gold or silver coin and it is never permitted in any kind of wares or goods or articles.”
Malik said, “There are certain transactions which if a long span of time passes after the transaction takes place, its revocation becomes unacceptable. As for usury, there is never anything except its rejection whether it is a little or a lot. What is permitted in other than it is not permitted in it because Allah, the Blessed and the Exalted, said in His Book, ‘If you repent, you have your capital back, not wronging and not wronged.'” 32.4 Conditions Permitted in Qirad.