The contract of istisna’a is a contract of sale (ba’i) which involves the future delivery of specified items to be manufactured or constructed by a manufacturer or a builder who is obliged to provide both the services and materials needed to fulfill the contract.

Ijarah is a contract that has a service or usufruct (manfa’ah) as underlying, and the lessor is neither required nor obliged to provide materials. In istisna’a, the manufacturer or builder provides both services and skills in addition to materials in the form of finished items or buildings.