This building consists of a large dome that was built during the latter part of the Fatimid period. It is said to commemorate the 'brothers of Joseph,' but who they were or whether indeed there was a real burial here is a matter of debate. The original tomb chamber under the dome is definitely worth visiting for the splendid carved plaster mihrab that occupies the whole of the qibla wall. The central niche is joined to two side niches to form a triple mihrab. The carving is very fine both in the floriated Kufic inscription of the Quranic verses and in the punched, stamped leaf forms that fill the spandrels of the arches.
Williams, Caroline. 2002. Islamic Monuments in Cairo: The Practical Guide. Cairo: American University of Cairo Press, 118.