至于第三条原则,即设立一位哈里发是全体穆斯林的义务,下面这段圣训已经证实了这一点。穆斯林圣训集录述,纳菲尔说:阿卜杜拉·本·欧麦尔对我说:我听见安拉的使者ﷺ说:

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:

“谁从服从真主的义务中收回了自己的手，他在复活日见到真主（SWT）时，将没有任何凭据可以为自己辩护；谁死的时候颈上没有效忠的誓约，他就是死于蒙昧时代（Jahiliyyah，即无明时期）的死亡。”在这段圣训中，真主的使者ﷺ使每位穆斯林都有义务在颈上担负对哈里发的效忠誓约，即Bay’ah，但他ﷺ并没有使每位穆斯林都必须实际给出这一效忠誓约。义务在于每位穆斯林的颈上都有一份效忠誓约，也就是说，哈里发的存在本身使其有权获得每位穆斯林颈上的效忠誓约。哈里发的存在是引发每位穆斯林颈上效忠誓约的根源，无论该穆斯林是否实际给出了效忠。至于哈里发职位的统一以及禁止同时拥有多于一位哈里发，这是因为穆斯林在《圣训实录》中从艾卜·赛义德·胡德里那里传述，他说真主的使者ﷺ曾说：

“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: