On a purely practical level, there would be little plant or animal life in a desert, certainly not enough to feed that many people for 40 years. And where would they get water? The story is fiction, just as the story of Jesus as Messiah. And it was embroidered upon and added to, as all legends are. All it takes is a little common sense to figure it out as an impossibility. Of course, if you’re assuming miracles, physics and biology don’t count and anything would be possible. Within theism anything is possible, which is why the concept of miracles is dismissed by intelligent people.