"...we sailed for fifteen days and came to Maqdashaw [Mogadishu], which is an enormous town. Its inhabitants are merchants... When a vessel reaches the port, it is met by sumbuqs, which are small boats, in each of which are a number of young men, carrying a covered dish containing food. He presents this to one of the merchants on the ship saying "This is my guest" ... Each merchant on disembarking goes only to the house of the young man who is his host...the host then sells his goods for him and buys for him, and if anyone buys anything from him at too low a price, or sells to him in the absence of his host, the sale is regarded by them as invalid."—Ibn Battuta, The Rihlah
What conclusion does this description from the 30-year voyage of the medieval-era African explorer Ibn Battuta support?