Why did Jem not want Scout to tell Atticus about Bob Ewell's comment in To Kill a Mockingbird? Was this a wise thing?

doesnt want to tellthat Bob
Ewell threatenedand him because he doesnt want him to worry.

Throughout the book, Jem and Scout are both maturing.  Scout is too young to really
understand what is going on in the beginning, but as time goes on she understands more and
more.  Jem, however, understands more.  He is old enough to appreciate the bigger
picture.

Jem and Scout learn of the threat from Miss Stephanie, the town
gossip.

Miss Stephanie told Aunt Alexandra in Jem's
presence €¦ that Mr. Ewell said it made one down and about two more to go. Jem told me not to be
afraid, Mr. Ewell was more hot gas than anything. (Ch. 25)

Bob Ewell is bent out of shape because of the treatment of his family and his daughter
at the trial.  He is embarrassed, and feels as if his family name was impugned by Atticus.  This
is the reason that he threatens Jim and Scout.  Scout may not really understand that, but Jem
does.  Jem does not really take the threat seriously, because he thinks that Bob Ewell is
harmless.

Jem is aware of the situation with Bob Ewell because of the
conversation he had with Atticus. Bob Ewell also threatens Atticus, and he does not take it
seriously either.  Ewell spits in Atticuss face.

It was
Miss Stephanie's pleasure to tell us: this morning Mr. Bob Ewell stopped Atticus on the post
office corner, spat in his face, and told him he'd get him if it took the rest of his life. (Ch.
22)

All Atticus had to say about this was that he wished
Ewell did not smoke tobacco.  He does not think that Ewell will do anything about it.  He
considers Ewell a small little man.  He tells Jem that he destroyed his last shred of
credibility at that trial (Ch. 22).  He was happy to allow Bob Ewell to spit in his face if that
allowed him to maintain his dignity and keep him from taking it out on his children.

Mr. Ewell turns out to be a little more than hot gas though.  He does attack the
children when they are walking home from Halloween.  Ifhad not been there to protect them, he
might have seriously hurt them.  As it was, Radley killed him, and that was the end of Bob
Ewell.

The disagreements between Jem and Scout are constant throughout the
book, but they change in complexity.  At first they just argue about who should play what part
in their make believe game.  Soon, they are arguing about issues of right and wrong, and life
and death.  It is part of growing up.  In each case, their arguments demonstrate the gap in
maturity between the two, but they also show that Scout is growing up.