“I went out and bought batteries. Unfortunately they weren’t included.” - Steven Wright
A young man is in a bind. His father is an insurance agent and makes his living quite dishonestly [he also sells dead batteries, on the side]. Is it permitted for the son to tell potential clients to stay away because of his father’s crooked ways? [His father obviously won’t listen to his son and cease from his behavior.]
Normally we know that it is permitted to relate lashon hara for “to’eles” [practical benefit] - to save someone from harm and the like. If you are helping somebody then your speech is not “ra” - evil. On the contrary, it is good! So of course the son should speak up!
Not so simple. Rav Nissan Kaplan Shlita [Kovetz Kol Torah Nissan 5761] notes that we only find that it is permitted to speak lashon hara for to’eles, but in our case there is also the issue of honoring parents. That is not overidden for to’eles. There is also a prohibition of “Arur makle aviv vi’imo” - Cursed is one who disgraces his mother or father. Telling people that his father is a crook is definitely a disgrace to his father. So in our case apparently it would be forbidden to say anything.
However we find in the gemara [13b] that Rochel told Ya’akov that Lavan is a cheat. We see that a child may speak negatively about a parent for a practical benefit. So maybe in our case it would be permitted for the son to warn potential clients.
The bottom line is that one is obligated to tell potential clients to stay away from the crooked father. By telling them, the son is preventing his father from sinning. We are all commanded to do what we can in order to save another person from sinning. That also explains why Rochel was allowed to tell Ya’akov that her father was dishonest [a “Ramai”]. She knew that he would try to cheat Ya’akov and she was trying to prevent him from doing so.
In a similar instance Rav Eliashiv ruled that a daughter whose father [a doctor] was stealing equipment from the hospital was obligated to say “Dad, you taught me that it is forbidden to steal and I am going to report you if you don’t return the stolen equipment.” Then she must carry through on her threat if he doesn’t do as told.
See Sefer Chasidim Simman 1087 and Chashukei Chemed - Megillah 161-164.
[Any practical questions should be brought to a competent Rabbi.]
This d’var halacha courtesy of Yeshiva University, yutorah.org.