How Many Banu Isra'im?

Musa'ala His salah tells the whole of Banu Isra'im quietly at night. We need to go, everyone, leave everything and let's move. So, they all went, how many were they? How many were they?' It's a good question. Some of the historians say, there was more than half a million. They're just walking and as they're gone, Phir'im gets the news. He says, what? They're going there, we are going to follow them. But Allah had already told Musa'ala Your salah, you are going to be followed. The two armies saw each other, when the two groups saw each