Qiyas is the legal principle introduced in order to derive a logical conclusion of a certain law on a certain issue that has to do to the welfare of the Muslim. The word Qiyas means “comparing with” or “judging by comparing with a thing”.
In Islamic law, Qiyas it refers to analogical deduction from the Qu’ran, the Sunnah and Ijma. In other words, Qiyas is a legal principle that extends an Islamic ruling from an original case to a new case because the new case has the same effective cause as the original case.
This can confirm Qiyas’ authentications that when Prophet (pbuh) choose Muaz Bin Jabal as Governor, he asked him what he will do if a problem arises. He said that he will follow the Qu’ran and if is not clear there then he will consult the Sunnah of the Prophet Muhhamd (pbuh) and in case if he fails to satisfy then he will use his own judgement (Qiyas). Prophet Muhammad (pbuh) encouraged him on listening to his reply.
Another hadith tells:
“Judge upon the Book of Allah, upon the Sunnah of the Prophet and if you do not find it in that, then use your personal opinion ”
Qiyas also means a shari’ah value from an original case to a new case because the latter has the same effective cause as the former.
There is no clear authorities of Qiyas in the Qur’an . However, the scholar quoted several proofs from the Qur’an and sunnah as well as the practice of the companions as an indirect evidence to support the utilization of Qiyas:
(Surah Al-Nisa 4 verses 105)
“We have sent to you the book with the truth so that you may judge among people by means of what Allah has shown you”
Based on the above verse, a judgement may be blessed on the guidance that Allah has clearly given or on that which bears close similarity to it.
Thus, exercising Qiyas is considered as following the guidance of the Qur’an. The Qur’an specifies the rational of its law either explicit or by reference to its objectives.