Urf


is an Arabic Islamic term referring to the custom, or 'knowledge', of a given society. It can also be translated as customary law. To be recognized in an Islamic society, must in principle be compatible with Sharia, but in practice tensions sometimes exist between the representatives of and those of Sharia. When applied, it can lead to the deprecation or inoperability of a certain aspect of fiqh.
is a source of Islamic legal rulings where there are no explicit primary texts of the Qur'an and Sunnah specifying the ruling, making it a form of customary law. can also specify something generally established in the primary texts.

Overview

;Terminology
The term, meaning "to know", refers to the customs and practices of a given society.
;History
was first recognized by Abu Yusuf, an early leader of the Ḥanafī school, though it was considered part of the, i.e genuine and not a formal source. Later al-Sarakhsī opposed it, holding that custom cannot prevail over a written text.
;Scriptural basis
The idea that custom is an authoritative source for Islamic law appears in the Quran and Hadith. One hadith narrated by Ibn Mas'ud stated 'Whatever the Muslim saw as good is good by God, and whatever the Muslim saw as evil is evil according to God.'"

Relationship to Sharia

Although this was not formally included in Islamic law, the Sharia recognizes customs that prevailed at the time of Muhammad but were not abrogated by the Qur'an or the Sunnah. Practices later innovated are also justified, since Islamic tradition says what the people, in general, consider good is also considered as such by Allah. According to some sources, holds as much authority as , and more than . is the Islamic equivalent of "common law".
In the application of, custom that is accepted into law should be commonly prevalent in the region, not merely in an isolated locality. If it is in absolute opposition to Islamic texts, custom is disregarded. However, if it is in opposition to, custom is given preference. Jurists also tend to, with caution, give precedence to custom over doctoral opinions of highly esteemed scholars.
In some countries such as Egypt, marriage in the way refers to a form of common law marriage that does not involve obtaining official papers issued by the state. The validity of that type of marriage is still under debate, and women may have fewer rights than under an officially-registered marriage.
In parts of Yemen where plays a significant role, it often coexists with Sharia. However, is promoted by the tribal sheikhs, whereas Sharia judges are either qāḍīs or sādah. Due to this different sociopolitical basis, the actual relationship between both legal phenomena varies from tribe to tribe. They can be seen as fully compatible or as two competing systems. Historically, the Zaydi Imams of Yemen often entered in conflict with local jurisdictions. In some cases they struck an agreement to separate the two jurisdictions by applying Sharia to "personal status matters" and to tribal matters.