Describe some of Amir's most severe injuries. What is the significance of Amir's injury to his lip?

Amir describes the fight with Assef. Assef had used brass knuckles, his favorite weapon from childhood, to beat Amir and knock out his teeth. He remembers his ribs, a bone in his face, and his nose breaking. He remembers that at one point, he began to laugh uncontrollably; even though Amir's body was broken, his spirit finally felt healed. It was Sohrab who saved him in the end. 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. The injury to his lip was reminiscent of Hassan's harelip.