Where can I get a Torah written half in Arabic and the other in Hebrew?
A Torah is only written in Hebrew. They are handwritten and cost tens of thousands of dollars. If you’re looking for a Chumash (the five books of the Torah in book form), they can be found in translation in any country that has Jews that speak the language you’re looking for. The problem with finding an Arabic translation is, because it is a Jewish holy book, most Muslim governments do not allow its publication – in any language. And there are not that many Arabic-speaking Jewish communities left in the world – most of them were forced to move to the US, France, and Israel after being persecuted in their home countries as an aftermath of the establishment of Israel in 1948. The great Middle Eastern Jewish rabbi and sage Saadya Gaon did a translation into Arabic that is still studied by Middle Eastern Jews today. I did some Googling and was unable to find a copy for sale, but that might be the best place for your friend to start.