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Those Macs are "build-to-order". They are difficult to find at an Apple Store, so what I recommend you is to call to the Apple Online Store in your country and buy your MacBook from there with an Arabic keyboard
I want my macpro with an arabic and english keyboard can you help me with that..?
If you are in the US, why don't you just order it from the US Apple online store? Look at the keyboard choices for example on this page:
Asking for a special order from a retail store sometimes works but sometimes does not.