When Shara made it incumbent upon the Ummah to appoint a Khalifah, it determined for her the method by which the Khalifah is appointed. This method is proven in the Book and the Sunnah. The Muslims who must give the bayah are those that are citizens of the Khilafah at that time. In the case where there is no Khilafah the Muslims responsible for giving the bayah are those living in the region where the Khilafah should be implemented. .

The method of electing the Khalifah through a bayah is proved from the example of the Bayah given by the Muslims to the Prophet (P.B.U.H), and from the order of the Messenger (P.B.U.H) to us, to pledge Bay’ah to the Imam. The Bayah of the Muslims to the Messenger (P.B.U.H) was not a Bayah on Prophethood, but a Bayah over ruling, for it was regarding action not belief. Therefore, Rasool Allah (P.B.U.H) was pledged allegiance to as a ruler, and not as a Prophet or a Messenger (P.B.U.H). This is because acknowledging the Prophethood and Messengership is linked to belief (Iman), and not a Bayah. Hence the Bayah to Him (P.B.U.H) was only in his capacity as the head of the state. .

The Bayah is also mentioned in the Qur’an and Hadith. Allah (S.W.T) says:.

"O Prophet! If the believers come to you to take the oath (Bay’ah) that they will not associate [in worship] anything with Allah, that they will not steal, that they will not commit adultery, that they will not kill their children, that they will not utter slander, intentionally forging falsehood, and they will not disobey you in any just matter (Ma’roof), then receive their oath (Bayah)." [TMQ: 60:12] In another verse Allah (S.W.T) says: .

Verily those who pledge their allegiance to you do no less than pledge their allegiance to Allah: The Hand of Allah is over their hands." [TMQ: 48:10].

Al-Bukhari narrated on the authority of Isma’il, who reported on the authority of Malik, who reported on the authority of Yahya bin Sa‘id who said: “Ubadah bin Al-walid told me, that my father told me that Ubadah bin al-Samit said: .

"We have pledged allegiance to the Messenger of Allah to listen and obey in ease and in hardship and that we do not dispute the matter (authority) with its people and that we stand for and speak the truth wherever we are and that in the service of Allah we would fear the blame of no one.” [Bukhari, Sahih, #7054 and Muslim, Sahih, #4748] .

Muslim has reported that Abdullah ibn Amru ibn al-As narrated that the Messenger of Allah (P.B.U.H) said: .

"Whosoever pledges allegiance to an Imam by giving him the clasp of his hand, let him obey him if he is able to do so, but if another comes along to dispute with him, then kill the latter." [Ahmad, Musnad, 3/10] ..

Also in Muslim it is narrated that Abu Saeed Al-Khudri reported that the Messenger of Allah (P.B.U.H) said: .

“If two Khulafaa’ were pledged allegiance, then kill the latter of them." [Muslim, Sahih, #1853] ..

Muslim narrated on the authority of Abi Hazim who said: “I accompanied Abu Huraira for five years and I heard him talk of the Prophet’s (P.B.U.H) saying: "Banu Israel used to be governed by Prophet, every time a Prophet died, another came after him, and there is not Prophet after me. There will be Khulafa’ and they will number many". They said: "What would you order us to do?" He (P.B.U.H said: "Fulfil the Bayah to them one after the other, and give them their due right, surely Allah will account them for that which He entrusted them with".” [Bukhari, Sahih, #3455] .

These texts from the Book and the Sunnah explicitly state that the method of appointing a Khalifah is by the Bayah. This was understood and practiced by all of the Sahabah. The bayah given to the rightly guided Khulafaa’ was clear in this regard. .