Somali was likely developed within Somaliweyn, it’s just that the language group as a whole likely migrated here- with the Omotic people likely being displaced in the process. The main theory is that the ancestors of the Somali, Oromo, Afar, etc etc were likely from Egypt/Sudan (where the Beja of Egypt and Sudan historically/currently are) and slowly migrated south. However this was a very very very very long time ago so there are a lot of ideas.So Somalia learned Somali after coming to Somalia hmm