Avoiding gossip is the stickiest commandment to keep. The stickiest subjects of gossip are shidduchim, job and school interviews, and the like. In such cases, it is justified to relay negative information about a third party, to let them know what they are getting into. But not always. You cannot just relay whatever you know.
"What do you know about this boy/ girl?" is a very dangerous question. Although you want to help the inquirer, there are rules and regulations that the Chafetz Chaim lists in Shemirat Halashon as to what is allowed to be relayed and what is forbidden. If you do have information that the person, at present, behaves with immorality (pritzut) or that he/she comes from a family with immorality, or that he/she degrades qualified Rabbis (apikorsut), or that he/she has an emotional or physical sickness that is not known to other people, such information should be mentioned relating shidduchim, in order not to transgress the law of לא תעמוד על דם רעיך, Do not stand by as your friend gets hurt. However, you are actually playing with fire if:
1. You are not 100% sure about the negative information even if your intention is only to warn the inquirer to look further into the matter
2. You have something against the person…..
3. The negative information about inappropriate behavior morals, illness or apikorsut was relevant only in the past, or for a short period, and the situation has since changed for the better
4. There is no substantial reason to believe that the negative condition will repeat itself
5. The information is not something that might affect their marriage or business relationship.
Relaying negative information in these situations constitutes Lashon Hara in its most severe form. A Rabbi who is very familiar with the laws of Shemirat Halashon must be approached to counsel you as to what you should/ should not say. If you cannot get to a Rav, and someone asks you, for shidduchim purposes, "What do you know about this boy/ girl?" Answer his question with a question. "What exactly do you want to know?"
At times, the parent of the boy/girl the person is inquiring about is in massive debt, has a sickness, a certain negative characteristic, shlom bayit issues or is in the process of divorce. And you are not sure that this will affect the marriage of the inquirer is asking about. Hold your tongue, till you ask a Rabbi who is familiar with these laws. If one of these issues is important to the inquirer, it is his responsibility to ask specific questions. He is the one who needs to ask a direct question that you, in your position, can answer. The only way to refrain from saying the wrong thing is to learn the laws of the Chafetz Chaim on a consistent basis. This subject is so complicated that someone recently wrote a whole sefer on answering questions regarding shidduchim.
This is a law that is very hard to understand. I want to let the inquirer know what he is getting into, and I have nothing against the one who is being inquired about. I am 100 percent sure about this information, these facts. Why can't I just let him know something about the person's past that he might, anyway, soon find out, and might be upset that he did not know before, or even upset at me for not having told him earlier? If I were looking into buying a car and asked a close friend/ family member who knew all about the car, I would want him to tell me everything. And, if he withheld part of the information, I would be upset with him. So, what's the difference? I asked my Rabbi to explain this law to me, and this is what he told me. This is a great insight into the G-dliness of Man, as well.
People are not cars; they are much more complex. People can correct themselves; they can change. They have good things and bad things, strengths that cover up weaknesses, and weaknesses that cover strengths. Cars are static, people are dynamic- there essence is constantly changing and subject to change. Also, there is a subjective way to look at things, and of course, it differs from one person to the other. What you would stay away from, others wouldn't. Things that bother you may not bother others. Sometimes, parents who are in debt help out their children more than those who are not. They can provide physical or emotional support, if not financial support. Even people who get "all the information" about the other side agree, two years into marriage that things are different from what they thought, despite all their research. Irrelevant information can also be subjective, or just a perspective. Only if a person asks specific questions about things that can hurt them can you relay negative information, and even then, only with great care.
Why did the Torah put the story of the Spies in juxtaposition to the story of Miriam's gossip about her brother and her punishment? Because these wicked people should have observed and internalized the lesson. (Rashi; Midrashim)The sin of the Spies was gossip about the Land of Israel. Didn't they have somewhat of a purpose in letting the people know what they were getting into? Didn't Miriam have a reason to tell Aharon that Moshe's chosen celibacy was improper? After all, if the Avot stayed married, how could he behave differently? And when Yosef brought negative reports of his brothers to Yaakov, he surely had good intentions. So, why did the Torah make such a big deal of these cases of Lashon Hara, and why did these people of stature suffer so greatly?
The answer is clear. To teach us that gossip is sticky. Despite good intentions, and despite a person's greatness, gossip remains an unavoidably sticky subject.
Rabbi Yosef Farhi