What is the significance of the passages in italics (a memory, a dream) on p. 69-72 in The Kite Runner?What is the purpose of these passages to the...

The purpose of the memories presented in italics in
Chapter 7 is to symbolically represent the themes of brotherhood, betrayal, and
sacrifice that are prevalent in the novel.  The italicized section opens with the memory
of Amir learning that he and Hassan were nursed as babies by the same woman.  This
"mother"-link draws Amir and Hassan together as brothers.  The strength and significance
of this bond needs to be established so that Amir's betrayal of Hassan is also more
significant.  Amir remembers the old man who proclaimed to tell them the truth:  Hassan
willingly opens himself up to have the old man see his truths; however, Amir refuses. 
This suggests that Amir is a person who will have demons to hide and who will run from
the truth rather than confront it.  Finally, the last memory is of the lamb at
slaughter, and Amir remembers the look on that lamb's face.  When Hassan is raped, Amir
says that the look on Hassan's face was like the lamb, a knowing sacrifice for some
higher purpose.  After this incident, Amir must struggle to repent and find goodness in
his own character.  So Hassan's sacrifice leads to Amir's
redemption.