The first time he describes Hassan’s appearance, the narrative uses a metaphor comparing Hassan’s cleft lip to a mistake made by a doll maker. This moment shows Amir’s early, immaturely cruel way of seeing Hassan’s birth defect:

And the cleft lip, just left of midline, where the Chinese doll maker’s instrument may have slipped, or perhaps he had simply grown tired and careless.

A cleft lip is a congenital disorder where a baby’s upper lip does not form completely, leaving a gap or split on that part of its face. There are varying degrees of severity for the condition, from a small notch to a large opening that connects to the nose. Describing this birth difference as a “doll maker's” mistake is derogatory on Amir’s part. It suggests that Hassan’s cleft lip is the result of either clumsiness or laziness. As a child, Amir imagines Hassan’s facial difference as something that could have been avoided if his creator had been more careful. This metaphor is one of many ways Amir distances himself from Hassan. By framing him as imperfect or lesser, made with “instruments” that “slipped,” he can continue to feel superior to his friend. Instead of seeing Hassan’s cleft lip as something he should be kind about, Amir judges it as a flaw. He sees it as a sign that Hassan is somehow unfinished or broken.