Definition: Qiyas literally [means] “to determine” and technically [means] to determine 1 a fara’ (derivative issue) from an Asl (root issue) to ascertain the hukm (ruling) and illat (cause).

Evidence: [Qiyas] is proven through revelation and common sense. In terms of the revealed [evidence], there is the statement of Allah Almighty, “fa’ tabiru ya ul al-absar”2 and the hadith of Mu’adh which is well known.

In terms of indicative [evidence], i’tibar3 is necessary [as per the ayat]. [An example of i’tibar] is to ponder on what has reached us from before [of the past nations] in regards to punishments [they recieved] due to causes stated about them4 . This is so that one may refrain from the causes to save from similar punishments as a consequence5 . Similarly, [an example of i’tibar is] to ponder on the literal meaning of a word to make a metaphor which other than the [literal meaning]; [this is] common.6 These are equivalent to Qiyas[Shar’i ].

Example: [Qiyas being i’tibar] is manifest in the declaration [of the prophet (peace be upon him)], ‘al-hintah bi al-hintah’ (wheat in exchange for wheat) as in Sell wheat in exchange for wheat. Wheat is measured in volumes and compared to its kind. His statement ‘mathalan bi mathalin’ is the [permitted] circumstance (hal) of that which was mentioned. Circumstances (ahwal) are conditions (shurut), imperative (amr) is for binding (ijab) and selling (bay’) is mubah (allowed). Hence, the imperative (amr) will hinge on the circumstance (hal) which [in turn] is a condition (shart). [This is supported] with the evidence of that which is mentioned in another hadith; kaylan bi kaylin (volume for volume) [in place of mathalan bi mathalin]. He meant from fadl, surplus in the amount not surplus in itself. Hence, it is permitted to sell one handful in exchange for two handfuls.7 The ruling of the source is that equality is necessary between the two in terms of [measurable] quantity and thereafter prohibition is determined due to neglecting the ruling8 of the imperative (amr).  [When the equality lapses] the ruling of prohibition of the source is established.  The trigger to the [ruling of the source] is measurement and type as equality is necessary in measurement between these assets which are same and equal. This is absolutely not possible except through measurement and type because equality occurs in form and meaning; this is [found] with measurement and meaning. The value of quality is dropped via the source. [Hence,] this is the ruling of the source.

Application: We have found rice etcetera to be same and equal. As such the surplus upon between the same types where the surplus is devoid of additional payment in a trade deal will have the same ruling of the source [relating to riba] exactly. Thus, we affirm the ruling [of the source] by way of doing i’tibar.

Example: [Qiyas being i’tibar] is manifest in punishments. Allah almighty says, ‘Hu al-Lazi akhraja al-Lazina kafaru min ahl al-Kitabi min diyarihim li awwal al-hashari ma zanantum’. Expulsion from homes is a punishment like execution. Kufr (disbelief) has the capacity to trigger [expulsion]. [The words], Awwal Hashar (the first occurrence) alludes to multiple occurrences of this punishment. Subsequently, we call on i’tibar to act upon that which there is no source. So likewise here [we ponder on the illah (cause) of a source to apply it to a fara’ (derivative issue) with the same ruling].

Principle: The asl (sources) in itself is based on an illah (cause) except that in this it is necessary that the criteria [be determined]. It is necessary before [establishing the criteria] from the established proof that it be representative of the case.

• 1Some have defined it to be “to extend the hukm from the asl”; this is incorrect as the hukm already exists, hence, it does not require ta’diyah (extension) rather only ibanah (exposition).
• 2Ponder! O those those who have understanding
• 3Apply something upon its equivalent (radd al-shay ala naziri)
• 4In terms of their enemity towards the message and the prophets.
• 5In simple terms, the determination of crime through set criteria and the application of the ruling thereof is in essence a form of qiyas.
• 6We use Qiyas in our day to day language through the use of metaphor which in essence is taking the components of one element and applying it to another; this is the very essence of Qiyas.
• 7So long as it does exceed the minimum unit of measurement which historically for volumes was half a sa’.
• 8The ruling is do not sell like for like items of weight or volume with a surplus.