My DH wanted to do the same, for exactly the opposite reasons. I disagreed vehemently, we had HUGE rows about it, but I'm holing firm. DS knows his name, introrduces himself and answers to it. Perhaps we oughtn't to have chosen such an ethnic name, but we did... we will change our family surname instead.
Your son is half your genes, and your family are not muslim, so it's easily understandable by anyone with sense that he is a 'product of 2 cultures' as it were. Both heritages worth celebrating and maintaining for his own sense of identity.
It's not like you called him George, or William or Harry - traditional 'Christian' names. Your DH didn't object to it at the time, so it's not like it ought to go against anyone's grain (and it's not their business either..)
It's a highly individual name, and a really lovely one in fact! If the book said it had roots in Arabic, it may have, but obscure ones. You both were doing what you thought was right at the time.
'God knows your intentions'
Please don't confuse the lad.