The word Khaleefah linguistically means ‘successor’ in the Arabic language. But, the Shari‘ah of Islam has given us another, more comprehensive definition of the word Khaleefah. The Prophet of Allah (saw) said, “...there will be no more prophets after me, only Khulafa‘a.” Bukhari

In this hadith the word Khulafa‘a is not referring to successors, but to heads of the Islamic State. The word Khaleefah is, therefore, taken to mean ‘that man who rules over a people by Islam,’ acting as the head of the State. The same Shari‘ah definition would apply if we used the word Imam, instead of Khaleefah, to indicate the head of State. And since in Islam, the bay‘ah is given only to a head of the State, both the words Khaleefah and Imam are pertaining to the head of the State.