Who is Sabri Salama from The Haj and what is their importance?

Sabri Salama was a sixteen-year-old boy, who worked as a mechanic for the Iraqi Army. His father had owned a garage and five trucks used to transport crops and supplies to Jaffa. The boy became separated from his family when the war began and thought they had gone to Gaza. He is unhappy in Nablus and wants to leave. He left Nablus with Ibrahim's family, doing the driving and the needed repairs to the truck. He stays with the family as they move around and settle in the Aqbat Jabar camp. He continues to work as a mechanic and becomes romantically involved with Nada. When Ishmael finds out, he sends Sabri away. Years later, he receives a letter from Sabri saying he is an active followed of Nasser.