How we cite our quotes:
At first, he had only been fascinated. He had never seen aircraft so close, for it was against the rules for Pilots to fly over the community. Occasionally. When the supplies were delivered by cargo planes to the landing field across the river, the children rode their bicycles to the riverbank and watched, intrigued, the unloading and then the takeoff directed to the west, always away from the community. (1.2)
Much of The Giver has to do with the way Jonas's responsibility as Receiver isolates him from the rest of his community. But it's interesting to note that the novel begins with this, a declaration of the community's isolation from the rest of the world.
"So there will be a whole part of your life which you won't be able to share with a family. It's hard, Jonas. It was hard for me." (13.50-51)
For The Giver, isolation has to do with the burden of duty. To break his isolation would be to share the memories he holds with others – which we know would cause them pain. In this way, The Giver is self-sacrificing.
"Go," The Giver would tell him tensely. "I'm in pain today. Come back tomorrow."
On those days, worried and disappointed, Jonas would walk alone beside the river. The paths were empty of people except for the few Delivery Crews and Landscape Workers here and there. Small children were all at the Childcare Center after school, and the older ones busy with volunteer hours or training. (13.80-81)
Jonas seems to be the only Twelve who is isolated because of his job. This is, needless to say, even more isolating for him.