Is it permissible to extend the maturity date and increase the debt amount in a prior contract of manumission (Kitabah)?
General Chapter
Al-Mughni
Book of Mukātaba (Contractual Manumission)
Primary text
It is presumed that extending the maturity date of a deferred debt in exchange for an increase in the principal amount is impermissible. This is because a debt whose term has been set cannot have its maturity date deferred by mutual agreement, nor can its term be changed. If the term is not deferred past its original due date, the increase made in exchange for that extension is invalid. Furthermore, this situation resembles forbidden ignorance-era usury (Riba al-Jahiliyyah), which is an increase in debt for an increase in the deferred period. This contrasts with the ruling on immediate payment, where advancing the payment allows for a concession, whereas here, more is taken than was originally contracted for, which is prohibited.
Supporting text
An alternative view suggests that such an agreement might be permissible, similar to the case where the debt is paid earlier. If they agree upon this change and one party subsequently retracts their agreement, they retain the right to retract, provided the retraction occurs before the fulfillment of the new terms. The underlying principle is that a deferred debt cannot be postponed beyond its due date or prematurely settled by agreement alone, although the debtor may choose to pay early, and the creditor may choose to defer receiving payment at its due date.