Q and TIA, thanks for that information on the word "Alafia".

It would not surprise me if the Yoruba word 'alafia' came from the Arabic word, as Islam {and the Arabic language} has been an important cultural factor in West Africa since at least the 11th century AD. There are a number of "traditional African" personal names that are variants of Arabic names. The same is probably true for African words which aren't names.