What happens in the giver chapter 8

Finally, when all the Twelves have gotten their assignments, the Elder addresses the fact that she skipped Jonas. She apologizes, and everyone ritualistically chants, "We accept your apology."
She goes on to say that Jonas has not been assigned; rather, he has been selected.
Selected to be…
The Receiver of Memory.
Evidently, this a big deal, because the crowd all basically gasps.
The Chief Elder explains that the community has only one Receiver at a time, and that the current Receiver—an old man—trains the next one.
Everyone looks over to the Committee of Elders where the current Receiver—indeed a very old man—sits. He has pale eyes, just like Jonas.
The Chief Elder explains that they tried to pick a new Receiver about ten years ago, but it failed. This is clearly an uncomfortable topic for everyone, so she quickly moves on.
There's no room for error here, she says, so they've been careful in selecting Jonas, who now has to lead what is portrayed as a mostly solitary life.
Oh.
Then she starts listing all of Jonas's qualities which qualify him to be The Receiver: intelligence, integrity, courage (there will be pain, she says), and wisdom (although Jonas doesn't have this yet, he'll soon be acquiring it. By the boatload).
There is one more quality, she says, "The Capacity to See Beyond."
Jonas is just about to object and explain that, actually, he doesn't have any special Capacity, when he looks over the crowd and sees them "change," the same way the apple once did.
So he says to the Chief Elder that yes, indeed, he does sometimes see something.
So everything is hunky-dory. The crowd chants his name and Jonas is both proud and fearful of what is to come.

It’s A lot But It Tells A lot Of The Chapter

Uh

It's a gift from god that allows people to bear witness to horror.