How can there be a consensus among the scholars on a matter for which there is a clear and authentic textual proof?

Ijma' (scholarly consensus) is the agreement of the qualified jurists (mujtahidin) of the Ummah, after the death of the Messenger of Allah, peace and blessings be upon him, in any era, on any matter. Its validity is supported by many texts from the Qur'an and Sunnah, including His, the Almighty's, saying: "And whoever opposes the Messenger after guidance has become clear to him and follows other than the way of the believers - We will give him what he has taken and drive him into Hell, and wretched is that destination" [An-Nisa':115], and His, the Almighty's, saying: "And if you disagree over anything, refer it to Allah and the Messenger, if you should believe in Allah and the Last Day. That is the best [way] and best in result" [An-Nisa':59], as well as hadiths that encourage adherence to the community. Among its benefits are raising the rank of a ruling to become definitive if its evidence was not definitive, or providing complete confidence in the religion and unifying the hearts of Muslims if the ruling was already definitive.