Decision of the Fiqh Academy on the Question of Custom
In the name of Allah, Lord of the worlds. May blessings and peace be upon our master Muhammad, the Seal of the Prophets, and upon his family and Companions.

Resolution no. (9) concerning custom:
The Council of the Islamic Fiqh Academy, convened at its fifth conference in Kuwait from 1 to 6 Jumada al-Ula 1409 AH / 10 to 15 December 1988 CE,
after examining the papers submitted by members and experts on the topic of “custom” and listening to the discussions held thereon,
resolved as follows:

First: The term ʿurf (custom) refers to whatever people habitually say, do, or omit and persist in; it may be acknowledged by the Sharia or it may not.

Second: When the custom is particular, it is binding upon those concerned; when it is general, it is binding upon everyone.

Third: A custom is recognized by the Sharia only when it fulfills the following conditions:
(a) It does not conflict with the Sharia. If it clashes with an explicit scriptural text or with a legal principle of the Sharia, it is deemed invalid.
(b) The custom is constant (ongoing) or predominant.
(c) The custom exists at the time the legal act is undertaken.
(d) The contracting parties do not explicitly stipulate otherwise; if they do, the custom is disregarded.

Fourth: A jurist—whether issuing a fatwa or delivering judgment—may not cling rigidly to what is recorded in the classical manuals without taking account of changing customs. Allah knows best.