According to Muslim jurisprudence, ijma' (the agreed view of the Sahabah) can serve as one of the sources of constitutional law or other legislation. In descending order of importance,te sources of law in Islam are (1) the Koran, (2) sunnah or tradition ,(3) ijma and (4) qiyas,which means analogical deduction,that is ,arriving at any answer by deduction from decisions in similar or parallel cases.