Parshat Ki Tetzei introduces the concept of a “wayward and rebellious son” (21:18-21). According to the Gemara (tractate Sanhedrin 68b) the qualifying conditions for a conviction are so onerous that it has never nor will it ever happen. Why would we need to know about a theoretical situation that will never occur?
Rav S.R. Hirsch explains that this hypothetical scenario teaches us important aspects about parenting and education. He explains that for a child to be considered wayward and rebellious there must be no possibility that anyone else is to blame for his actions. The fact that this will never happen means that there is always an outside influence that can be repaired or improved and we are encouraged to look inwardly to help others. What started out as a focus on the child ends up being an opportunity for introspection by those around him. In a world replete with blame and faults, focusing on what we can personally refine, correct and enhance will help correct actions of others around us.