One of the narrations widely known among Sunni Muslims is the narration to which they have made recourse in order to argue that “the Commander of the Faithful, Ali (A.S.) married out his daughter, Umm Kulthum, to Umar”. The narrations regarding Umm Kulthum’s marriage to Umar have been recorded by Sunni Muslims in their most famous books. Some of these narrations relate to the allegation that the Commander of the Faithful, Ali (A.S) married his daughter to Umar. Some relate to the marriage of Umm Kulthum after Umar’s death and others relate to the event of her death and her son.They have transmitted these narrations arguing that the narration is authentic and that Umar did, in fact, marry Umm Kulthum, the daughter of the Commander of the Faithful, Ali (A.S). This lecture reveals the discrepancies in the reports making them look clearly contradictory.