Gemara

(Rava): "...Karu v'Lo Damu" - David said 'if I would be torn, my blood would not spill (because it drains from me when people shame me). When my tormentors learn the four Misos of Beis Din, they stop learning to ask me 'which is the death penalty for Bi'ah with a married woman?'

I answer 'it is choking, and he has a share in the world to come, but one who makes someone blush has no share in the world to come.'

Bava Metzia 58b (Mishnah): Ona'as Devarim (verbal affliction) is forbidden. One may not ask the price of an item if he has no intent to buy it. One may not say to a Ba'al Teshuvah 'remember your prior deeds!' One may not say to a convert's son 'remember your ancestors' deeds!', for it says "v'Ger Lo Soneh v'Lo Silchatzenu."

(Beraisa): "Lo Sonu Ish Es Amiso" forbids Ona'as Devarim. If one is suffering afflictions, one may not say the way Iyov's friends did "an innocent person does not perish". If donkey-drivers ask to buy grain, he may not say 'go to Ploni. He sells', and he knows that Ploni never sold. One himself knows whether he intends to pain another. It says about such matters "v'Yareisa me'Elokecha."

(R. Yochanan): Ona'as Devarim is worse than deceit in a sale. It says "v'Yareisa me'Elokecha" regarding the former, but not regarding the latter.

(R. Elazar): Ona'as Devarim is worse, for it afflicts the person himself, not just his property.

(Rav Shmuel bar Nachmani): Ona'as Devarim is worse, for it cannot be returned (undone).

(R. Chanina): Everyone who goes to Gehinom leaves, except for... one who makes another blush, or coins a derogatory nickname for someone.

Question: Giving a bad nickname is included in making him blush!

Answer: If he is already used to the name, he does not blush.

(Rava): One who makes another blush has no share in Olam ha'Ba.

(Mar Zutra bar Tuvya): It is better to cast oneself into a furnace than to make someone blush. We learn from Tamar - "Hi Mutzeis v'Hi Sholchah" (the only way to save herself would have embarrassed Yehudah, so she did not).

(Rav Chanina brei d'Rav Idi): "Lo Sonu Ish Es Amiso" refers to one's fellowman, i.e. he also observes Torah and Mitzvos.

(Rav): A man must be very careful not to afflict his wife. Women are prone to cry, and Hash-m is quick to punish when the victim cries.

(R. Elazar): The gates of prayer were locked after the Churban - "Sosam Tefilasi." The gates of tears were not locked - "Dim'asi Al Techerash."

(Rav Chisda): All the gates (of prayer) were locked, except for gates of (one who suffered) affliction - "Hash-m Nitzav Al Chomas Anach."

(R. Elazar): Hash-m punishes for everything through a Shali'ach, except for affliction - "uv'Yado Anach."

Rishonim

The Rif (Bava Metzia 32b, Rambam (Hilchos Mechirah 14:12-14,18) and Rosh (Bava Metzia 4:22) bring these teachings. (The Rambam omits that Ona'as Devarim applies only to one who observes Torah and Mitzvos.)

Nimukei Yosef (DH Omar citing Semag Lav 171): "Amiso" teaches that the Isur applies only to one with Yir'as Shamayim. Mechilta d'R. Yishmael (Mishpatim Reish 18) permits afflicting one who afflicted you. Such a person is not Amisecha. One may disgrace one of ill repute (Megilah 25b) and excommunicate such a Talmid (Mo'ed Katan 17a). If one transgressed a mid'Rabanan law, one may call him a transgressor (Shabbos 40a).

Rambam (14): If a matter of Chachmah was asked, one may not ask Almoni, one who does not know this Chachmah, what he thinks. The same applies to all similar cases.

Magid Mishneh: The Gemara did not discuss if a matter of Chachmah was asked, but one may learn it from the Isur to direct people seeking to buy grain to one whom he knows does not sell.

Kesef Mishneh: Rashi connotes that one who tells donkey-drivers to ask Ploni intends to embarrass Ploni. Alternatively, he intends to embarrass the donkey-drivers.

Rambam (15,16): If one afflicts a Ger (convert) verbally or monetarily, he transgresses three Lavim.

Rambam (Hilchos Teshuvah 3:14): One who coins a nickname for someone, or calls him by a nickname, has no share in the world to come.

Kesef Mishneh: Rashi connotes that if he is used to the name and does not intend to embarrass him, it is permitted. The Rambam did not limit the Isur to a derogatory name. He includes one who is used to the name and it does not seem derogatory to him. Even so, it is forbidden.

Tosfos (Sotah 10b DH No'ach): Making one blush is not listed among the Aveiros for which one must forfeit his life, for it is not explicit in the Torah.

R. Yonah (Avos 3:11): Making one blush is derived from murder.

Poskim

Shulchan Aruch (CM 228:1): Just like Ona'ah in a sale is forbidden, also Ona'as Devarim is forbidden: Ona'as Devarim is worse, for it cannot be returned, and it afflicts the person himself, not just his property. One who screams due to Ona'as Devarim is answered immediately.

Rema: Some say that the Isur applies only to one with Yir'as Shamayim. If one afflicted himself, you may afflict him.

SMA (4): Some explain that if one afflicted himself, i.e. Ploni, Ploni may afflict him. This is wrong. If so, it should have said 'if one afflicted you!' Also, the same applies if he afflicted others (for he is not Amisecha)! Rather, it refers to one who disgraces himself. The Torah did not command us to honor such a person. The Nimukei Yosef wrote this after one who lacks Yir'as Shamayim. However, if this were the reason, so he should have said 'for he does not fulfill Mitzvos.' Rather, he said 'he is not called Amisecha', i.e. civilized, refined people. Ir Shushan says that one without Yir'as Shamayim disgraces himself, so one may afflict him. This is wrong. It attributes what was taught (one without Yir'as Shamayim) to what was not taught (one who disgraces himself)!

Aruch ha'Shulchan: Some permit Ona'as Devarim of a Rasha, for perhaps it will cause him to repent. It is permitted if he intends for this. The same applies to one who afflicts himself, i.e. he goes in a bad path and thinks that it is straight. He is not in the class of civilized, refined people

Shevet ha'Levi (8:309:3): The Levush is primary. Amisecha excludes one who could observe and does not. If one was raised not to observe Torah, he is blameless! One may not afflict him, even though his deeds are evil. The Aruch ha'Shulchan is unlike the Poskim. It is improper to afflict a Rasha, but one does not transgress for this, for he is not Amisecha.

Sefer ha'Chachmah (in Mordechai ha'Aruch, brought in Bach 1): My Rebbi says that "Amisecha" was written only about Ona'as Devarim, but Ona'as Mamon applies even to one who does not fulfill Mitzvos I disagree. If so, Ona'as Mamon is more stringent than Ona'as Devarim. The Gemara said oppositely! Perhaps for both we exclude only a Nochri, but one may not afflict any Yisrael. However, it seems that one may not tell a Ba'al Teshuvah 'remember your prior deeds', but one may say so to others!

Bach (1): Rochel's sons were Resha'im (they kept Kilayim in their fields), so Chachamim fulfilled their mother's command to give her clasp to her daughter, just to punish her sons (Bava Basra 156b). R. A. of Rangsporg asked, where do we find that we may steal from a Rasha? He answered that we may if we have no other way to force him to fulfill Divrei Torah. If we may lash his body, all the more so we may strike his money! If so, Ona'as Devarim of a Rasha is permitted, and almost Ona'as Mamon! This requires investigation.

Shevet ha'Levi (8:309:4): Surely Ona'as Mamon is forbidden. Poskim forbid Ona'as Devarim of a Ger even if he does not observe Torah.

Shulchan Aruch (2): One must be very careful about Ona'as Devarim and Mamon of a Ger, for the Torah forbids this in many places.

Shulchan Aruch (3): One must be very careful not to afflict his wife, for she is prone to cry.

SMA (5): A woman's nature is to cry due to a small pain.

Shulchan Aruch (4): One may not ask 'how much do you want for this item' if he does not want to buy it. One may not tell one who seeks grain 'go to Ploni' if he knows that Ploni does not have to sell. One may not tell a Ba'al Teshuvah 'remember your prior deeds!' One may not say to a convert's son 'remember your ancestors' deeds!' If one is suffering afflictions, one may not speak to him the way Iyov's friends spoke to him. If a matter of Chachmah was asked, he may not ask one Ploni, who does not know this Chachmah, what he thinks. The same applies to all similar cases.

SMA (6): Iyov's friends spoke to him that way because he spoke harshly towards Hash-m.

Shulchan Aruch (5): One may not coin a derogatory nickname for someone, even if he is already used to the name, if he intends to embarrass him.