The fact that Islam put forward certain broad economic rules...

The fact that Islam put forward certain broad economic rules and related them to the `urf [prevailing standards of conduct] concept has a special connotation for notions like isra'f and tabdhi'r [wasting and squandering], faqr and ghina' [poverty and needlessness], al-nafaqa't al-muta`a'rifah [customary allowance], al-manfa`at al-mualah [lawful profit], ma`u'n [basic need], riba' [usury], mithli'yyah and qi'mi'yyah [fungibility and being ad valorem], circulation and depression of cash currencies, _ama'n [liability], individual and social damage, [impediment], _aru'rah [urgency], al-ma#lahat al-`ulya' [the higher expediency], being asbaq [preceding] in waqf, being `aqdi'y [contractual], being bay`i'y [exchange], trade through tara'_i [mutual agreement], being qimari'y [gamble], lahw, and even `ada'lah [justice], ~ulm [injustice], ta`addi' [transgression], and akl al-ma'l bi al-ba'>il [misappropriation of property].

Thus, `urf intervenes when these concepts change, often due to change in conditions, and consequently, as a result of change in the `urfi' [commonplace] view of the subject the judgment also changes as we saw in the issue of sha>ranj [chess] for example. However, the most important element on which the Islamic system concentrates is the element of intervention by the mujtahid, just wali'y al-amr in the economic life.

This intervention has its own criteria, rules, and what the late al-@adr calls the penetrating beams that illuminate Islam's positions and give it the spirit of the system and its promising goals1.

In such a system, the wali'y has the obligation to take advantage of his social power and true commitment to Islam and the Islamic expediency of the ummah and, through consultation with the masters of knowledge and expertise, carry out his duties which can be summarized as the following: Identification of the best methods and executive arrangements for the enforcement of the fixed rules of Allah, e.g.

looking for the best way to eliminate riba' in the society while preserving the positive activities performed by the banks. Filling the public domain with laws in accordance with the supreme Islamic expediency while preserving, as much as possible, the primary rule regarding the various cases. Determining the extent to which the conditions are favorable for the enforcement of Islamic rules and institutions.