Hassan was born a Hazara, and this would keep him always in the lowest class of society in Afghanistan. In The Kite Runner by Khaled Hosseini, Hassan grows up with Amir, the son of Hassan's father's employer, and their friendship is not equal. Of course it is unequal because Amir is from a higher class (he is a Pashtun), but it is also unequal because Hassan always defers to Amir because he loves Amir unselfishly. Amir and Hassan used to climb trees and use their slingshots to shoot walnuts at the neighbor's one-eyed dog. Amir says,
Hassan never wanted to, but if I asked, really asked, he wouldn't deny me. Hassan never denied me anything.
Even more, Hassan and Amir would get in trouble for pelting the dog with nuts and other mischief,
[b]ut [Hassan] never told on me. Never told that shooting walnuts at the neighbor's dog was always my idea.
These quotes from Hassan's childhood foreshadow the life Hassan is going to lead as time passes. When Amir needs something, like the blue kite to win his father's approval, Hassan will win it for him--at a terrible and humiliating cost. When Amir feels so much guilt for not standing up to Assef as he was assaulting Hassan, he plants evidence that Hassan stole from him. Amir makes the accusation and Hassan falsely admits to Amir's crime and is sent away because of it. This is the pattern of their relationship and of Hassan's sacrificial and loving nature, and Hassan will eventually lose his life by returning to the city, making his final sacrifice for Amir and Baba.
The boys are often seen as brothers, despite their financial and class differences. Amir says Hassan's father, Ali,
would remind us that there was a brotherhood between people who had fed from the same breast, a kinship that not even time could break.
Hassan and I fed from the same breasts. We took our first steps on the same lawn in the same yard. And, under the same roof, we spoke our first words.
Mine was Baba.
His was Amir. My name.
This quote is significant and revelatory because we later learn that the two boys really are brothers, and of course once again Hassan's first interest is Amir. These relationships drive all the major events of Hassan's life as well as Amir's (who, by the way, ends up raising Hassan's son, his nephew).
These quotes appear early in the novel and serve as a kind of prophetic foreshadowing of what is ahead for Hassan, especially because of his pure and unselfish love for Amir, a brother who proves himself unworthy of it.