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

Amir introduces Hassan by describing his face in detail, ending with his most distinctive feature—Hassan’s cleft lip, an opening in the upper lip up to the nose. A cleft lip is not an unusual birth defect and can be corrected surgically; the fact that Hassan’s cleft lip was not corrected indicates the poverty he was born into. Readers learn that the defect symbolizes something more from Amir’s explanation that the cleft lip is the result of an accident or even a careless act of creation: The cleft lip implies that Hassan is an unfortunate being.

As confided to a neighbor’s servant by the garrulous midwife, who had then in turn told anyone who would listen, Sanaubar had taken one glance at the baby in Ali’s arms, seen the cleft lip, and barked a bitter laughter.

Even at Hassan’s birth, the cleft lip marks him and sets him up for future heartache. His own mother laughs bitterly at the birth defect, a reaction that some readers might infer as her interpreting her baby’s defect as a result or punishment of her infidelity. This scorn is soon spread by gossips through the community. The cleft lip sets Hassan apart from others from the day he is born.

Never mind that to me, the face of Afghanistan is that of a boy with a thin-boned frame, a shaved head, and low-set ears, a boy with a Chinese doll face perpetually lit by a harelipped smile.

Amir equates Afghanistan with Hassan, underscoring the importance of Hassan in his life. But he uses the word harelipped to describe Hassan’s smile. Harelip is a term that is synonymous with cleft lip but that some consider derogatory because it likens the lip of a human to the lip of a hare. In Amir’s mind, a cleft lip symbolizes Hassan, who in turn symbolizes their childhood home.

I wished I too had some kind of scar that would beget Baba’s sympathy. It wasn’t fair. Hassan hadn’t done anything to earn Baba’s affections; he’d just been born with that stupid harelip.

Baba gives Hassan the birthday gift of having his cleft lip corrected. But rather than feel happy for Hassan, Amir feels jealous. Amir constantly tries to win his father’s approval and affection, something Baba seems to resist giving Amir, yet Hassan seems to receive because of his birth defect. In Amir’s mind, Hassan’s cleft lip has caused a rift between Amir and Hassan, and also between Amir and Baba.

The impact had cut your upper lip in two, he had said, clean down the middle. Clean down the middle. Like a harelip.

Here, Amir reflects on a doctor describing to him what happened to his lip when Assef beat him. The injury created a split in his mouth much like Hassan’s cleft lip. Doctors sew the cut, but Amir learns he will always have a scar. Amir has become like Hassan, both physically and emotionally: he is now able to stand up for those he cares about, as Hassan stood up for him. The scar, which he will always have, will be a symbol of his redemption.