Ijma’ is defined as the unanimous agreement of the jurists of the Muslim community of
any period following the demise of the Prophet Muhammad on any matter. Unlike the Qur’an and Sunna, ijma’ does not directly partake in divine revelation.
As a doctrine and proof of Sharia, ijma’ is basically a rational and yet binding proof.
The term qiyas, according to the Muslim jurists, means analogical reasoning, i.e. concluding from a given principle embodied in a precedent that a new case falls under this principle or is similar to this precedent on the strength of a common essential feature called the ‘reason’ or ‘illa (Rahman 1979,71)
Ijtihad literally means exerting efforts or strenuousness, but technically it means exercising independent juristic reasoning to provide answers when the Qur’an and Sunna are silent (An-Na’im 1996, 27). The exercise of ijtihad, in a broader sense, is relevant to the interpretation of the Qur’an and Sunna.