The Hujjiyah of Al-Ijmaa’ as a source for the Islamic Ahkaam is a place of agreement amongst the majority of the Fuqahaa and ‘Ulamaa of Usool ul-Fiqh in addition to what is built upon that in terms of the obligation to follow and not violate a ruling based upon it. However, they differed in respect to which Muslims the Ijmaa’ is taken from.

The most well-known Ijmaa’s that the ‘Ulamaa of Usool ul-Fiqh and Fuqahaa adopted are:

Ijmaa’ As-Sahaabah, Ijmaa’ Ahl ul-Madinah, Ijmaa’ Al-Ummah AlIslaamiyah in a certain era or period, Ijmaa’ Al-Mujtahideen in a certain era or time and Ijmaa’ Ahl ul-Bait in the view of the Shee’ah.

I will first deal with the Hujjiyah of Ijmaa’ As-Sahaabah because most of the ‘Ulamaa from the Usooliyeen and Fuqahaa counted it as a legitimate and valid Ijmaa’ and then I will address the Ijmaa’ of the Islamic Ummah.

The Ijmaa’ As-Sahaabah is regarded as a Hujjah (proof) due to the following evidences:

1 - Allah’s commendation and praise (Thanaa’) upon the companions (Sahaabah) of the Messenger of Allah (saw) in the Qur’aan: