Historically, this is the same with muslim western africa such as timbuktu which used arabic manuscripts. Argubly it isn't a specific thing to somalis, but it also applies to a lot of muslim countries.
Arabic was English-ing before English. The sheer spread of its use is absolutely mind-boggling to think about considering it didn't benefit from modern radio, television, the internet, and modern sea navigation. I mean from parts of India and China all the way to Spain and Morocco. From as deep in West Africa as Nigeria to all the way on the other side of the continent in Somalia or Tanzania then onward into the Indian Ocean world as far flung as the Philippines and Indonesia. Subxanallah...