What is the ruling on including a penalty clause in a contract for early termination or delayed installment payments? Does the ruling differ if the fine is a percentage?

The penalty clause for delaying debt repayment is, by consensus, impermissible, because it is explicit usury, unlike the penalty clause for non-performance or delay in performing agreed-upon works. The latter is valid and permissible if the other party incurs damage. The penalty clause related to delaying installment payments is not permissible. As for the penalty clause related to the tenant terminating the contract before the end of the term with a known fine, it also appears to be impermissible, because the legitimate penalty clause is one that takes into account the actual damage incurred by one party and the absence of a valid excuse for the other party. The Council of Senior Scholars and the Islamic Fiqh Academy have ruled that the penalty clause is valid and must be upheld unless there is a legitimate excuse that nullifies it, and if it is excessive, justice and fairness must be referred to. The penalty clause is not to be enforced if the party upon whom it was stipulated proves that their breach was due to circumstances beyond their control, or that the party for whom it was stipulated did not incur damage. In a lease contract, the rent is binding on the tenant for the entire period as long as the lessor has made their benefits available to them, provided the tenant has no valid excuse for rescinding.