Why after their escape, do Ishmael and the boys go back into the village of Mattru Jong?

The boys needed money for food. They were hungry, and their need for money outweighed the danger of returning to Mattru Jong.

We got hungrier day after day, to the point that our stomachs were hurting and our visions blurred at times. We had no choice but to sneak back into Mattru Jong, along with some people we encountered on the path, to get some money we had left behind, so that we could buy food.