Question? Why couldnt they marry?

Ok so there was this scene between the main character and a religious leader (Imam I think). And the Imam suggests that Polat (I think)could meet and marry a nice woman from that Iraqi village, but Polat replies that he couldn't because his Imam (in Turkey I guess) would never allow it. So I ask why? Is it because the the woman in Iraq would be of a different sect or church of islam, is it a ethnic issue or national? Or is it just because his Imam back home would want him to marry a woman from that Turkish village.