Cute. Did you come up with that yourself, or are you just repeating what you heard at the mosque? It's a common, erroneous, disingenuous, and muslim argument. Please excuse the redundancy.
Besides all of that, it is a deliberate sidetrack, intended to obscure the fact that muslims hate the Jews. It is a silly argument, implying that since the arabs are semites, they can't be anti-Semitic, therefore they can't hate Jews. Illogical muslim BS, but I'm being redundant again.
One only wonders if one is willfully ignorant of the meaning of the term "anti-Semitic". While both the Jews and the Arabs are Semites, anti-Semitic doesn't mean anti-Arab. The term was coined by Jew-haters, and means just that - Jew-hater.
Try a dictionary. Go ahead and look up "Semite", and pat yourself on the back for being so clever. But don't close the book until you've looked up "anti-Semite", and then go stand in the corner.
I don't think I will. Feel free to start without me, though.