Islamic law is different from any conventional law. The structure of Islamic law is not only constructed by the perspectives of the intellectual people, but it was constructed in general for the educated and the non-educated. This is because the element of rational thinking is not sufficient enough to apply in Islamic law. For example, we can see the annihilation of the nature which was led by the rational and scientific thinking (Hallaq 2009, 15). The content of rational thinking, thus must be predetermined by the God who has revealed message and knowledge through the Quran and the Prophet (Hallaq 2009, 14). The Islamic law is born through the relationship of reasoning and revelation.
Islamic law or Shari’a was built upon four main sources which are: The holy Quran, Sunnah, consensus and analogical reasoning. The Quran is the predominant source of law, which means nothing should surpass the text of the Quran. The inscription in the Quran tells about the knowledge of human beliefs, the mighty God himself and how we should behave in this temporary world, compromising good and bad deeds. Hence, it is no doubt that a jurist has to refer to the Quran first as the main source as it embodied the words from the God itself.
The second sources of Islamic law should be Sunnah, any verbally transmitted record of the actions, statements and way of life of Muhammad. The one that a jurist pays attention is Hadith, a narrative form of what Muhammad had said (Hallaq 2009, 16). One of the examples of hadith is “He who plants, without permission, in a lot owned by other people cannot own the crops although he is entitled to a wage [for his labor].” (Hallaq 2009, 16). This exemplary of hadith which convey the righteous concept of fairness is derived to make Islamic law specifically in the area of property. The problem with Hadith would be identifying whether the Hadith is true or false as forgery of hadith is everywhere which is deemed for political and personal purposes. Another strain a jurist would face would be encountering one or more hadith related to the case he/she is trying to solve. The solution to this was making the former hadith far more superior than latter hadith (Hallaq 2009, 18). One of the example to find out which is more superior is by finding out whose first transmitter of hadith is the closest to Muhammad. But if the procedure fails, another method that a jurist can apply is abrogation; in which one of the hadiths is made to repeal, and thus cancel out the effects of, another (Hallaq 2009, 18).
If the jurist still cannot find the law through the Quran and Hadith which maybe due to the metaphor and grammar in Quran which is hard to interpret and failure to find the right hadith, consensus or ijma’ is the resort being the third source of Islamic law. Consensus means agreement from all the community through the process of reasoning by mujtahid (a jurist who conducts jihad) by using the Quran and Sunnah as references. A number of perspectives on one fact, characterized Islamic law into legal pluralism which features adaptability to different societies and has the ability to change over time (Hallaq 2009, 27). Even though the cases related to consensus is limited, they were regarded as most significant (Hallaq 2009, 22).
The last source of Shari’a is legal reasoning or qiyas. The method of Qiyas is referred as analogy method. The familiar example would be determining whether wine is considered halal (food or drinks which adhere to Islamic law, means it can be consumed) or haram? (cannot be consumed by Muslim). There is a Quranic text which prevents you from consuming anything that will make you hallucinated, dizzy, wasting your time or unhealthy, but there is no Quranic text that said wine is haram. Hence, the similarity in terms of the effect of the wine and the drinks mentioned in Quran will make Wine haram for all the Muslims. The example mentioned has all the four elements of qiyas in which the first one, the new case must have a legal solution. The second one, the original case must be stated in either the Quran, hadith or sanctioned by consensus. The original case for this example would be the text in Quran that prohibits anyone from drinking anything that will harm you physically or mentally. The third element is the attribute common to both the new and original cases. For this example, the common attribute would be the negative effect of both the new and original cases. The final element is the legal norm found in original case must be transposed to new case (Hallaq 2009, 23).
These are all the four main sources of Shari’a which is established by Muslim community; a holistic law which can be implemented in the Muslim world.