研究伊斯兰教法的学者中，认为“习惯”（al-‘Urf）是伊斯兰立法渊源（Masdar）的人，承认它作为证据（Daleel）适用于《古兰经》和圣训中没有经文（Nass）规定的情形。如果某种习惯与《古兰经》或圣训相违背，则该习惯被拒绝，不予采纳。

The ‘Ulamaa who have said that Al-‘Urf is a Masdar (source) for the Islamic legislation acknowledge it as a Daleel in the case where there is no text (Nass) from the Kitaab or the Sunnah. If the ‘Urf was contrary to the Kitaab or the Sunnah, then it is rejected and not taken.

马立基耶学派和哈乃斐学派在没有经文（Nass）对某一现实情况作出裁决的地方运用“习惯”（‘Urf）。他们认为，“习惯”是指人们在相互交往（Mu’aamalaat）中已经形成惯例、习以为常的做法；违背被认可的“习惯”，在他们看来会导致困难和艰难。这一观点的依据是安拉至高的话语：

The Maalikiyah and Hanafiyah utilised the ‘Urf in other than the place of the text i.e. where there a Nass (text) for the Hukm (judgment) upon a reality from the realities does not exist. The ‘Urf in their view is that which the people have made habitual and become accustomed to in their Mu’aamalaat (societal transactions) and violating the considered ‘Urf, in their opinion, leads to difficulty and hardship. This is based upon the statement of Allah Ta’Aalaa:

因此,马立基学派与哈乃斐学派的学者说:经由健全习俗所确立的事项,而非由败坏习俗所确立的事项,即是由沙里尔的证据所确立的。

For that reason, the ‘Ulamaa of the Maalikiy and Hanafiy Madh’habs said: The established (matter) by the Saheeh ‘Urf and not the Faasid is established by a Daleel Shar’iy.

《Al-Ashbaah Wa-n-Nazhaa'ir》的注释者说："由习惯（'Urf）确立的事物，与由法律证据（Daleel Shar'iy）确立的事物相同。"

The Shaarih (explainer) of the book: ‘Al-Ashbaah Wa-n-Nazhaa’ir’ said: “The established (matter) by ‘Urf is established (proven) by a Daleel Shar’iy.

As-Sarkhasy (rh), who belongs to the Hanafi madhhab, said in *Al-Mabsoot*: "The matter established by ʿUrf is like the matter established by text (An-Nass)." The meaning of this statement of his indicates that a matter established by ʿUrf is established by a daleel other than the text (Nass). Chinese translation: 由哈乃斐学派的艾斯-萨尔哈西（愿真主怜悯他）在《穆卜苏特》中说："由习惯（ʿUrf）所确立的事，等同于由经文（An-Nass）所确立的事。"他这句话的含义表明，由习惯所确立的事，是由经文以外的另一种凭据所确立的。

As-Sarkhasy (rh), who is from the Hanafiy Madh’hab, said in ‘Al-Mabsoot’: “The established (matter) by the ‘Urf is like the established (matter) by text (An-Nass)”. The meaning of this statement of his indicates that the established matter by the ‘Urf is established by a Daleel that is other than the text (Nass).

黑纳菲派的法学家们达成共识：若Qiyaas（类比推理）与‘Urf（习惯惯例）相悖，则舍弃Qiyaas，并将此称为“‘Urf之Istihsaan（善择）”。他们认为，若某条概括性经文属于Zhanniy（或然性）文本，则‘Urf可以限定（Takhsees）其普遍含义。举例而言，有传述称先知ﷺ禁止附带条件的买卖。然而，尽管如此，大多数黑纳菲派与马立克派仍允许任何已被‘Urf所认可的条件，即使该条件与交易相关联。

The Fuqahaa’ of the Hanafiyah have settled to leave the Qiyaas if it opposes the ‘Urf and they have called that ‘Istihsaan Al-‘Urf’. They said that the ‘Urf specifies (Takhsees) the ‘Aamm (general) if the general text was Zhanniy (indefinite). An example of leaving the generality in the Zhanniy text for the sake of the ‘Urf is that it was related that the Nabi (saw) forbade the sale that was accompanied by a Shart (condition). However, despite that, the majority of the Hanafiyah and Maalikiyah permitted every Shart (condition) that the ‘Urf has given consideration to and even if that condition was linked with the trade.

fuqahāʾ 也在“宽泛”（Muwassaʿ）与“狭窄”（Mudayyaq）的情形中依据习惯（ʿUrf）作出裁断。例如，哈乃斐学派认为：若商人在市场上把某物卖给他人，而双方并未明确约定价款是提前支付还是延后支付，但依据习惯，卖方每周五都会收取一笔既定的费用，那么就按此习惯付款，无需另行详述，这依循的是ʿUrf（习惯）。沙斐仪学派则认为：若有人发誓不吃鸡蛋，而他吃了鱼卵，他并不违背誓言，因为依据ʿUrf，“蛋”这个名称并不适用于鱼卵。

The Fuqahaa have also sought judgement in the ‘Urf in respect to the the Muwassa’ (broad/wide) and the Mudayyaq (narrow). So the Ahnaaf, for example, held that if the trader sells something in the market to someone else and the two contracting parties have not expressed explicitly whether the cost is to be brought forward or delayed, whilst it was known by way of custom that the seller would take a known cost every Jumu’ah, then the payment will be made upon that basis without the need for elaboration, in accordance to the ‘Urf (custom). Ash-Shaafi’iyah held that if a person swore an oath not to eat eggs, he would not have broken his oath if he had eaten fish eggs because the name of ‘egg’ is not applied to them in accordance to the ‘Urf.