Bay` al-kali bi-kali

(Lit. Sale of a debt for a debt) Bay`al- kali' bi-kali' is a type of sale which is prohibited. Islamic jurists use this term to describe several different types of debt-for-debt exchanges. The most well-known of these is the exchange in which a lender extends his debtor's debt repayment period in return for an increase on the principal i. e. interest. The term kali' is a synonym for debt.