要使"ʿUrf"（习惯）得到重视，并以之为依据建立或推导律例，学者们规定了以下条件：

For the ‘Urf to be given consideration and for Ahkaam to be built or based upon it, the following have been stipulated as conditions:

1 – 它不与经文（Nass）相悖，即它代表一种有效的习惯（Saheeh ‘Urf），例如允许Istisnaa'（订制某物）；而非一种无效的习惯（Faasid ‘Urf），例如在婚宴（Waleemah）上提供酒类。

1 – That it is not contrary to the Nass (text) where it represents a Saheeh ‘Urf like the permissibility of Istisnaa’ (ordering a thing to be manufactured) and is not a Faasid ‘Urf like managing alcohol at Waleemahs (celebration dinners).

2 – 该“ʿUrf”（习惯／惯例）是“Muttarid”（普遍的）或“Ghaalib”（占主导的），即这种“ʿUrf”在其所属民众中广泛流行，为他们所熟知，并被他们所遵行。所谓占主导，是指大多数人都按照它行事。

2 – That the ‘Urf is Muttarid (general) or Ghaalib (predominant) meaning that the ‘Urf is widespread amongst its people, well-known to them and acted upon by them. The predominance means that the majority of the people act in accordance to it.

3 – 即“习惯”（‘Urf）在付诸实行之前就已存在，然后这一“习惯”一直延续到实行的时候，使二者并行不悖、同时并存。也就是说，在行为发生的时候，这一“习惯”正在被遵循。

3 – That the ‘Urf had arisen prior to the time of acting upon it and then the ‘Urf continues until its time so that it proceeds hand in hand with it simultaneously. That means that at the time of the conduct, the ‘Urf is being acted upon.

4 – 不存在任何言语或行为能够确立与惯例(‘Urf)相反的内容。例如,如果依惯例出口费用应由买方承担,而两位订约方约定由卖方承担,那么惯例便被舍弃,而采用两位订约方所约定的内容。依他们的说法,这种情况下的法则(Qaa'idah)是:"凡依惯例确立而未经提及的事项,若已有相反的约定,则不再成立。"此说引自伊兹·本·阿卜杜·赛拉姆(‘Al-‘Izz Bin Abdis Salaam)的《法则》(Qawaa'id,即原则)第2卷第178页。

4 – That there is no speech or action that establishes the opposite of the ‘Urf. This would be like if it was from the ‘Urf that the fees of exporting were upon the buyer whilst the two contracting partners agreed for it to be upon the seller. In this case the ‘Urf would be dropped and what the two contracting parties had agreed would be taken. The Qaa’idah in this case according to them states: ‘That which is established by ‘Urf without mention is not established if the contrary has been stated”. This is taken from the ‘Qawaa’id’ (principles) of ‘Al-‘Izz Bin Abdis Salaam volume 2 page 178.