His title could be the Khalifah, the “Imam” or the “Amir al-Mu’minin”. These titles have been narrated in sound Ahadith and in the Ijma’ of the Sahabah. The Khulafa’ Al-Rashidin (first four Khulafa’) have held such titles. .

Abu Said Al-Khudri reported that the Messenger of Allah said: “If the pledge of allegiance (Bay’ah) has been taken for two Khulafaa’ kill the latter of them.” (Muslim, Sahih, #1842).

‘Abdullah ibn Amr Ibn al-‘Aas reported that he heard Allah’s Messenger say: “Whoever pledged allegiance to an Imam giving him the clasp of his hand and the fruit of his heart shall obey him as long as he can ...” [Muslim, Sahih, #1844] .

Auf Ibn Malik reported that he heard the Messenger of Allah (P.B.U.H) say: “The best of your Imams are those whom you love and they love you and who pray for you and you pray for them ...” [Muslim, Sahih, #4782]. .

In these ahadith the title of the ruler that executes the divine rules in Islam is the Khalifah or the Imam. .

The most authentic reports regarding the title “Amir al-Mu’mineen,” came from the hadith of Shihab Al-Zuhri reported by Al-Hakim in al-Mustadrak [vol.3, p.73, #4480], which was authenticated by al-Zahabi [in the Talkhis]. Al- Tabarani has reported a narration regarding which Al-Haythami declared all transmitters of sound character. Al-Hakim narrates the hadith as follows: .

“Ibn Shihab narrated that ‘Umar ibn Abdul Aziz asked Abu Bakr ibn Suleiman ibn Abi Haythma…“Who was the first to write from Amir al-Mu’minin?” He said, “Ash-Shafa’ told me, who was from the first female emigrants, that ‘Umar ibn al-Khattab (ra) wrote to the governor of Iraq to request two strong men so as to ask them about Iraq and its people. He sent to him Labeed ibn Rabeeah and Adi ibn Hatim. When they arrived to al-Madinah they halted their two camel rides in the courtyard of the masjid and entered into the masjid. They suddenly saw Amr ibn al-Aas, and said, “Ask O Amr for us the permission to see Amir ul-Mu’mineen!” Amru said, “By Allah, you called him by his right name. He is the Amir, and we are the believers (mu’mineen).” Then Amru jumped and entered before ‘Umar, Amir ul-Mu’mineen and said, “Assalamu Alayka ya Amir ul-Mu’mineen (Peace be upon you O Amir of the believers).” ‘Umar said, “What made you think of this name, O ibn al-As? Allah knows you have to justify that which you say.” He said, “Labeed ibn Rabeeah and Adi ibn Hatim arrived and they camped their two camel rides in the courtyard of the masjid and came to me and said ask O Amru for us the permission to see Amir al-Mu’minin!’ By Allah they gave you the right name; we are the believers (mu’mineen) and you are our Amir.” Since then, they started using this title in writing.” Ash-Shifa’ was the grandmother of Abu Bakr ibn Suleiman. After this the Muslims continued to call the Khulafaa’ after ‘Umar (ra) by this title.” [See also Bukhari, Adab al-Mufrad, #780].