Kuhusu kanuni ya tatu, kwamba kuanzishwa kwa Khalifa mmoja ni wajibu kwa Waislamu wote, Hadith ifuatayo imethibitisha hili. Muslim amepokea kutoka kwa Naf‘i kwamba alisema: ‘Abdullah Ibnu ‘Umar aliniambia: Nilimsikia Mjumbe wa Allah ﷺ akisema:

As for the third principle, that the establishment of one Khaleefah is an obligation on all Muslims, the following Hadith has confirmed this. Muslim narrated from Naf ’i that he said: ‘Abdullah Ibnu ‘Umar said to me: I heard the Messenger of Allah (pbuh) say:

"Atakayejitoa kwenye utiifu kwa Allah, atakutana na Allah (SWT) siku ya Kiyama bila kuwa na hoja yoyote ya kujitetea; na atakayekufa wakati hakuna bay'ah shingoni mwake, atakufa kifo cha siku za Jahiliyyah (ujinga)." Katika Hadith hii, Mjumbe wa Allah ﷺ ameifanya kuwa wajibu kwa kila Muslim kuwa na bay'ah, yaani kiapo cha utiifu kwa Khaliifa, shingoni mwake, lakini hakuifanya kuwa wajibu kwa kila Muslim kutoa bay'ah hiyo. Kilicho wajibu ni kuwepo kwa bay'ah shingoni mwa kila Muslim, yaani kuwepo kwa Khaliifa ambaye ana haki ya bay'ah shingoni mwa kila Muslim kwa sababu ya kuwepo kwake. Kuwepo kwa Khaliifa ndilo jambo linalozalisha bay'ah shingoni mwa kila Muslim, bila kujali kama Muislamu ametoa bay'ah kwa vitendo au la. Kuhusu umoja wa Ukhaliifa na katazo la kuwa na Khaliifa zaidi ya mmoja, hili ni kutokana na kile Muslim alichopokea kutoka kwa Abu Sa'id Al-Khudri kutoka kwa Mjumbe wa Allah ﷺ kwamba alisema:

“Whoever takes off his hand from obedience to Allah, he will meet Allah (swt) on the Resurrection Day without having any proof to show for himself; and who dies while there was no pledge of allegiance on his neck, he dies a death of the days of Jahiliyyah (ignorance).” In this Hadith, the Messenger of Allah (pbuh) has made it compulsory on every Muslim to have a pledge of allegiance, i.e. Bay’ah to a Khaleefah on his neck, but he (pbuh) did not make it compulsory for every Muslim to give the pledge (Bay’ah). For the obligation is the presence of a Bay’ah on every Muslim’s neck, i.e. the existence of a Khaleefah who is entitled to a Bay’ah on the neck of every Muslim by his existence. The existence of the Khaleefah is the matter which initiates the Bay’ah on every Muslim’s neck, regardless of whether the Muslim has effectively given the Bay’ah or not. As for the unity of the Khilafah and the prohibition of having more than one Khaleefah, this is due to what Muslim narrated from Abu Sa’id Al-Khudri from the Messenger of Allah (pbuh) that he said:

"Wakati kiapo cha Bay'ah kimechukuliwa kwa Makhalifa wawili, muueni wa mwisho wao." Hii inathibitisha wazi kwamba ni haramu kwa Waislamu kuwa na Khalifa zaidi ya mmoja.

“When an oath of Bay’ah has been taken for two Khulafaa’, kill the latter of them”. This clearly proves that it is forbidden for the Muslims to have more than one Khaleefah.