Thabit bin Dinar better known as “Abu Hamzah Thumali” is one of the great Shia narrators and a contemporary of several infallible Imams (A.S.). His title “Thumali” is pronounced somehow like “Somali” but there is no connection between this narrator and Somalia and there are different reasons to prove this:
1. The word “Somali” is written with the Arabic letter ‘Saad’«صاد» in the beginning just as «الصومال»، but the word “Thumali” is written with the letter “Tha” «ثاء» in the beginning.
2. Somalis are generally from the black race but there is no report in any historical resources to indicate that Abu Hamzah Thumali was from a black race. Had he been black, he would have been known in history just as Bilal was known to be black.
3. “Thumal” means backrest or something on which a person reclines. It also means remnant in Arabic and there is a clan also called “Thumala” or “Banu Thumala” which has been recorded as a part of a bigger race named “Azad”, the very tribe to which “Mubarrad’, the famous Nahwi (expert of syntax) belongs.
4. Generally speaking, whoever lives at a place is most likely from the same place. Any other claim in this regard is in need of a proof.
Having said the above, we would say with all due respect to our Muslim brothers in Somalia, that based on historical facts recorded in history, Abu Hamzah Thumali belongs to one of the clans in the Arabian Peninsula. He is not considered to be among the migrants from outside of the Peninsula.
 - Ibn Manzur, Muhammad bin Mukram, Lisan al-Arab, vol.11, p. 94, Dar Sader, Beirut, 1414 A.H.