If someone says something to offend you, can you just reply with a “Shutup!”, or will this be considered as hurting one’s feelings? This is a serious question. If it is a sin how else can you let someone know that their remarks are not appreciated in a way that they will stop?
While sheket means quiet, religious texts more often use the word shtika to refer to silence. The famous Rabbi Akiva is noted for saying, “a safety fence for wisdom is silence” (Pirkei Avot/Ethics of the Fathers 3:13). Elsewhere in the Talmud it is written, “the best medicine of all is silence. When Rabbi Dimi came, he said: ‘In the west they say a word is worth a sela, silence two selas” (Talmud Megillah 18a).
By extolling the merits of silence, the sages were not trying to hush a gathering of noisy, rambunctious youth. Rather they were discussing a character trait. Jews may joke, Jews may debate, and Jews may even argue, but Judaism places tremendous importance on peace. Knowing when to refrain from speaking is often the best way to maintain peace. Whether this means refraining from gossip, holding back a sharp retort or not trying to prove that one person knows better than another, shtika is the silence of self-discipline. That is why the recommended remedy to employ when one finds oneself about to say something one shouldn’t, is to tell oneself Sheket...Bevakasha.
(nice text from http://www.jewishtreats.org/2016/09/sheketbevakasha.html )
Well, if you THINK you CAN hurt a person by saying 'shut up', so of course you cannot say to this person 'shut up', because of the probability to hurt someone's feeling (even worse if more people seeing).
A more lenient way of think is to think 'this person won't be hurted' (if a friend or something else), but we have to remember that there are people watching us and it is not a polite way to talk with a fellow person, can you see a great rabbi like Shalom Arush or Rav Kaduri (blessed his memory) saying 'shut up' to someone?!
Even if this person is saying something you strong disagree, you have more polite ways to talk, or even better, say to yourself: 'Sheket...Bevakasha'.
- The rule is עביד איניש דינא לנפשי (B"K 27b) - we can see that is allowed to prevent one's damages. Also, Rambam posek so in Hil. Sanhedrin Ch.2 12:
"יש לאדם לעשות דין לעצמו אם יש בידו כח, הואיל וכדת וכהלכה הוא עושה - אינו חייב לטרוח ולבוא לבית דין, אף על פי שלא היה שם הפסד בנכסיו אילו נתאחר ובא לבית דין, לפיכך אם קבל עליו בעל דינו והביאו לבית דין ודרשו ומצאו שעשה כהלכה ודין אמת דן לעצמו – אין סותרין את דינו"
Therefore one is allowed to take measures to prevent mental or psychological damage to himself without turning to a Bait Din.
- The measure of this rule is (as many others of this kind) "הכל לפי המבייש והמתבייש" (Mishna B"K 8.1) it can not be pre-defined:
"בשת הכל לפי המבייש והמתבייש."
Shame? All depends on the one who shames and the one who is shamed.