Rahim Khan seeks out Hassan, who now lives in another city with his pregnant wife, because he is getting older, still living alone in Baba’s house, and has trouble taking care of it on his own. He seeks Hassan to com live with him and initially Hassan refuses but after Rahim Khan tells Hassan about Baba’s death in America, Hassan becomes emotional and eventually grants Rahim Khan’s request. Hassan picks up and moves, perhaps because he himself really has no other family besides his wife. We learn in this passage that Ali, Hassan’s father, has been killed.
In the book The Kite Runner Rahim Kahn had been best friends with Baba and Amir. After Baba had escaped to Americahe had asked Rahim to keep care of his place. Rahim is also aware that Hassan is Baba's son.
When Hassan was a child Rahim Kahn had watched him grow up and knew that he deserved to have more. However, he was also aware hat the boy could not get his fair due because he was born illegitimately from a Hazara woman.
Rahim Kahan was the one Hassan had told about his rape as a child. Rakim is left alone and older and I believe that he wants to give something to Hassan. He wants him to come and stay in the big house, but Hassan will not do it. He is very honorable and will only stay in the house in which he was born on the property. Through bringing Hassan back Rakim Kahn gains a family as well.