As for the points on which they differ:
Abu Ḥanīfah holds that a wife’s maintenance is not extinguished by the mere passage of time only when a judge has ruled it obligatory; by that ruling it is treated as a debt and therefore does not lapse. Without such a judgment, however, it lapses with the passing of time, just like the maintenance owed to relatives.
Al-Shāfiʿī maintains that a relative’s maintenance does not lapse in the following cases:
- If the liable person authorizes someone else to spend on his relative. Once permission is granted and the expenditure actually takes place, the amount becomes binding upon the one who gave the authorization and does not fall away.
- If a qualified judge formally fixes the maintenance; the judge’s decree converts it into a debt owed by the liable party.
In this detail the three schools—Ḥanafī, Shāfiʿī, and Ḥanbalī—are essentially in agreement.
Shaykh al-Islām said, “I know of no scholar who has held that the maintenance of a relative becomes a debt for time already past, except where the person incurred the expense on loan with the permission of a judge.”