ما أوجه الشبه والفروق بين الإجارة الموصوفة بالذمة والاستصناع؟

The commonality between istisna' (manufacturing contract) and the hiring of a described object for which one is liable (ijarat al-mawsuf fi al-dhimma) is that the contracted object is non-existent at the time of the contract. The difference between them is that the materials from which the contracted object is composed come from the manufacturer in an istisna' contract, and from the hirer in an ijara contract. So, in ijara, the object is from the hirer and the work is from the hired person, whereas in istisna', both the object and the work are from the manufacturer.