after (Beni) Merin, name of a Berber tribe of nomads and shepherds

What does beni mean in this context? Here is reference to the Beni Merin tribe, there are also the Beni Israel people in India. One-Look and Encyclopaedia.com give no real help that I could find except that beni seems interchangeable with bene, which perhaps brings in the Bene Gesserit in Frank Herbert’s Dune series, although that may be coincidence!