إجماع
Ijmāʿ
Consensus of the scholars of a period on a ruling; one of the sources of Islamic law.
What it means
The Sunni schools take four sources of law: the Quran, the Sunnah, ijmāʿ and analogy (qiyās). Consensus means agreement among qualified scholars of an age on a point of law. The Prophet is reported to have said that his community will not agree on error (Ibn Majah, graded hasan by some), and the idea is also argued from the Quran (4:115).
What the sources say
Scholars have debated whether it can truly be known, and the schools differ on its scope. A few matters, such as the five daily prayers, are accepted by all Muslims.