Arabic (دين) for debt. A dain comes into existence as a result of a credit transaction, contractual agreement, or any transaction or action financial obligation. More specifically, it is incurred either by way of trade (sale or purchase), lease, or whatever form of financial or non-financial transactions. The debtor is under obligation to return the debt (whether it is a money amount or an object- a’ariyah) without being charged any additional amount over the principal or face value. Debts, in Islamic shari’a, are, and shall be, always interest-free (riba-free) whether that riba is monetary or in kind.

Dayn is more comprehensive than loan (qard). All loans are necessarily debts, but not all debts can be deemed as loans.

Dayn comes in various forms including dayn hal, dayn muajjal, dayn muwathaq, dayn mushtarak, dayn marju, dayn thabit, etc.