On the Development of Custom as a Source of Law in Islamic Law: Al-rujū'u ilā al-'urfi ahadu al-qawā'idi al-khamsi allatī yatabannā 'alayhā al-fiqhu

Although classical Islamic legal theory did not recognize custom as a source of law, Muslim jurists-in particular, the Hanafis-discussed the status of custom already in the pre-classical period. Custom was incorporated into Islamic law in a variety of ways: by including certain practices in the category of sunna or ijmā'; by appealing to judicial preference (istihsān) and to secondary sources of law, such as fatwās; and by using legal fictions (hiyal). Because these methods were not always adequate to deal with the questions that specific practices presented to the jurists, there was an increasing tendency among later Hanafi jurists to recogize custom as a source of law.