In the community of The Giver, anyone who commits three transgressions is released.
Jonas’s mother, who works for the Department of Justice, explains what happens if you break a rule three times.
"You know that there's no third chance. The rules say that if there's a third transgression, he simply has to be released." (ch 1, p. 9)
Like everyone else, Jonas occasionally breaks minor rules. He brings an apple home when it changes, wondering what happened to it. He is anonymously but publically reprimanded.
When Jonas escapes, he breaks three major rules. These three rules alone could get him Released.
First, he had left the dwelling at night. A major transgression. Second, he had robbed the community of food: a very serious crime, even though what he had taken was leftovers... Third, he had stolen his father's bicycle. (ch 21, pp. 165-166).
Jonas knows that taking Gabriel is also a serious crime. He is worried about getting caught because Gabe was scheduled to be killed, and both of them would be killed if they are caught.
In Jonas’s world, there is no compassion. They kill people for minor offenses, just to prevent anyone from being uncomfortable. Everyone gets along, and everything is perfect. There is a darker side to this perfect world.
Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book) (p. 9). Houghton Mifflin Harcourt. Kindle Edition.