Is a delay penalty permissible on installments, whether intentional or due to an excuse? Is it permissible to waive a portion of the debt upon settling the remainder before its due date? What is the ruling on selling an item purchased on installments for cash to exploit its value?

For installment sales to be permissible, several conditions must be met. It is not permissible to impose a penalty for late payment of installments, whether the delay is excusable or not, because that constitutes usury (riba). Similarly, it is not permissible to stipulate a reduction of part of the debt in exchange for prompt payment (ٍSet and Accelerate). The price of the commodity must be fixed at the beginning of the contract without any increase, decrease, or calculation of temporal interest. It is not permissible for the buyer to sell the installment-purchased commodity for cash at a price lower than its deferred purchase price (bay’ al-’inah - re-selling to the original seller). However, selling it to another party to utilize its cash value (tawarruq - monetizing) is permissible, provided that the seller does not explicitly or implicitly commit to selling the commodity to another buyer.