a caliph must be a member of the tribe of the Prophet (the Quraysh) ... moreover, caliphs ruled societies that the Islamists do not consider to have been Islamic (the Ottoman Empire)." This is not the view of the majority of Islamist groups, as both the Muslim Brotherhood and Hizb ut-Tahrir view the Ottoman state as a caliphate. Religious basis Qur'an The Quran uses the term khalifa twice. First, in al-Baqara, 30, it refers to God creating humanity as his khalifa on Earth. Second, in Sad, 26, it addresses King David as God's khalifa and reminds him of his obligation to rule with justice. In addition, the following excerpt from the Quran, known as the 'Istikhlaf Verse', is used by some to argue for a Quranic basis for a caliphate: In the above verse, the word Khulifa (the plural of Khalifa) has been variously translated as "successors" and "ones who accede to power". Several schools of jurisprudence and thought within Sunni Islam argue that to govern a state by Sharia is, by definition, to rule via the caliphate and use the following verses to sustain their claim. Hadith The following hadith from Musnad Ahmad ibn Hanbal can be understood to prophesy two eras of the caliphate (both on the lines/precepts of prophethood). In the above, the first era of the caliphate is commonly accepted by Muslims to be that of the Rashidun Caliphate. Nafi'a reported saying: Hisham ibn Urwah reported on the authority of Abu Saleh on the authority of Abu Hurairah that Muhammad said: Muslim narrated on the authority of al-A'araj, on the authority of Abu Hurairah, that Muhammad said: Muslim reported on the authority of Abdel Aziz al-Muqrin, who said: Prophesied caliphate of the Mahdi Many Islamic texts, including several ahadith, state that the Mahdi will be elected caliph and rule over a caliphate. A number of Islamic figures titled themselves both "caliph" and "al-Mahdi", including the first Abbasid caliph As-Saffah. The Sahaba of Muhammad Al-Habbab Ibn ul-Munthir said, when the Sahaba met in the wake of the death of Muhammad, (at the thaqifa hall) of Bani Sa’ida: Upon this Abu Bakr replied: Then he got up and addressed the Muslims. It has additionally been reported that Abu Bakr went on to say on the day of Al-Saqifa: The Sahaba agreed to this and selected Abu Bakr as their first Khaleef. Habbab ibn Mundhir who suggested the idea