In chapter 19, Amir dreams about a scenario that closely resembles the scene Rahim Khan shared with him of how Hassan died:
His hands are tied behind him with roughly woven rope cutting through the flesh of his wrists. He is blindfolded with black cloth. … He is muttering something under his breath. I step closer. A thousand times over, he mutters. For you a thousand times over. … He lifts his face, I see a faint scar above his lip. I see the barrel first. Then the man standing behind him. He is tall, dressed in a herringbone vest and a black turban. He looks down at the blindfolded man before him with eyes that show nothing but a vast, cavernous emptiness. … I see the face behind the plume of smoke swirling from the muzzle. I am the man in the herringbone vest.
What is the significance of Amir casting himself as Hassan’s executioner in the dream?