Shia sources also record further details of the event. They state that those present congratulated Ali and acclaimed him as "Amir al-Mu'minin", while Ibn Shahr Ashub reports that Hassan ibn Thabit recited a poem in his honour. However, some doubts have been raised about this view of the incident. Historian M. A. Shaban argues that sources regarding the community at Medina at the time give no indication of the expected reaction had they heard of Ali's appointment. Ibn Kathir meanwhile suggests that Ali was not present at Ghadir Khumm, instead being stationed in Yemen at the time of the sermon.