The word “Imâm” comes from an Arabic root signifying to aim at, to follow after, most of the derivatives of which partake, more or less, of that idea. Thus Imâm means, primarily, an exemplar, or one whose example ought to be imitated. It is applied in that sense, κατ εψōΞην, to Muhammad, as being the leader and head of the Muslims in civil and religious matters, and also to the Khalîfahs, or legitimate Successors, as his representatives in both capacities. It is also given—in its religious import only—to the heads of the four orthodox sects, namely, the el-Hanafy, esh-Shâfa'y, el-Mâliky, and el-Hánbaly; and, in a more restricted sense still, to the ordinary functionary of a mosque who leads in the daily prayers of the congregation—an office usually conferred on individuals of reputed piety, who are removable by the Nâzirs, or wardens, and who, with their employment and salary, lose the title also.

The term is used in the Kurân to indicate the Book, or Scriptures, or record of a people; also, to designate a teacher of religion. Hence, most probably, its adoption by the Muslims in the latter sense. “When the Lord tried Abraham with certain words, which he fulfilled, He said, I have made thee an Imâm to the people.” Again, referring to Abraham, Isaac, and Jacob, “We have made them Imams that they may direct others at our command.” And, again, “We delivered to Moses the Book, therefore be not in doubt of his reception thereof, and we ordained it to be a guide unto the children of Israel. And we appointed some of them to be Imams to direct the people according to our command.”