الإجماع
al-Ijmāʿ
Consensus: the agreement of qualified scholars on a ruling, accepted as a source of Islamic law after the Quran and Sunna.
What it means
Ijmāʿ means agreement. In Islamic law it names the agreement of the qualified jurists of a given age on a legal question, and the schools count it among the sources of law after the Quran and the Sunna. Once such agreement is established, later scholars treat the ruling as settled. Jurists base the authority of consensus on texts such as 4:115, which warns against following a path other than that of the believers, and on a saying reported in several forms that the Prophet’s community will not agree on an error. Faruqi counts it with the sources from which Islamic law is derived.
Often misunderstood as
Some picture it as a vote of the general public or a majority decision, but it refers to the agreement of those qualified to give legal rulings.
What the sources say
Scholars disagree about who counts for consensus, whether it extends beyond the Companions, and whether it can be known to have taken place. Some, such as Ahmad ibn Hanbal, were cautious about claiming it.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 52, listed as AL IJMĀ'. The definition is restated here.