Condonation of usury in contract functions with a new reflection on the penalty clause

According to the Eghtefar rule that has been adopted from jurisprudential texts, the non-conformity of the subsidiary and followed is the essential and undeniable principle. The rational rule describes the relationship between subsidiary (subordinate) and followed (origin). Thus, what is obligatory to be observed in followed, may not be necessary in subsidiary. One of the important and practical implications of the Eghtefar rule is the condonation of usury in contract functions. Hence, although conditions such as similarity and taking delivery and handing over in contract are necessary in followed, they will still be ignored if they are obeyed. Given that, some have believed the contractual penalty clause that is more excessive than the original amount of the contract to be usury and invalid. In this article, based on Eghtefar rule, this issue has been doubted. It is proved that contractual penalty clause is not usury and invalid.