how did sorahb save amir's life?

Amir was lying on the ground with Assef on top of him, preparing for another blow, when Sohrab begged him to stop. He was aiming his slingshot at Assef's eye, just as his father had done half a century before. Assef tried to jump on Sohrab, who shot him and in doing so, gouged out his eyeball. As Assef rolled on the floor in pain, Sohrab helped Amir to the car. Farid drove away as fast as he could as Amir lost consciousness.