Is it permissible to say, as some people do, "Egypt is the mother of the world (Umm al-Dunya)"?

There is no religious impediment to using the phrase "Umm al-Dunya" (Mother of the World). Some scholars and historians have used it to describe major cities such as Istanbul, Baghdad, and Egypt. Ibn Khaldun described Egypt as "Umm al-Alam" (Mother of the World).