I don't think the foreigner they talk about is the one we know but maybe someone from the same nation. As to where that is, I've always doubted it'd be Greece I feel like Persia is more fitting. I know I can't expect this to follow and irl timeline but depending on which era this takes place in (it looks like a very early one) Greece would only be at it's early ancient stage and not really a nation yet and Persia developed earlier than Egypt even.