After the building of the Tabernacle was completed, Moses commanded that a reckoning be made of all the metals donated for the building and their uses.1 Moses did this in order to be "clean in the eyes of… the Jewish people."2 The lesson we take from here is that a person must behave in a way that is beyond reproach, both the reproach of G‑d and of his fellow man. In a similar vein, Rabbi Yehudah HaNasi states3: "Which is the right path for man to choose for himself? Whatever is harmonious for the one who does it, and harmonious for mankind."

For this reason, several precautions were taken when the priest would enter the Temple treasury to withdraw funds. The priest would not wear shoes and would have no pockets in his clothes, insuring that it was impossible for him to conceal a stolen coin in his pocket or shoes. He would also talk to others the entire time that he was inside the treasury so that he could not hide coins in his mouth. In addition, a poor or seemingly greedy priest was never chosen for this task so as to minimize suspicion in every way possible.4

Other precautions employed in the Holy Temple:

  • People could not say that they had pilfered some of the Temple's flourThe families that were in charge of baking the showbread for the Holy Temple would never eat white bread in their homes, so that people could not say that they had pilfered some of the Temple's flour.5
  • The families that were in charges of grinding and preparing the incense would not use any perfume at all, so they could not be suspected of using the incense of the Temple.6

Avoiding Suspicion in Charity Distribution

  • In ancient times, when collecting for a communal charity fund, collectors would always work in pairs so that one would "oversee" the other. The fund distribution was overseen by a group of three.7
  • A trustworthy manager of a charity fund is not obligated to give a reckoning of the monies distributed.8 Nevertheless, it is better if he does so. If his honesty is questioned, he is obligated to do so.9
  • Charity collectors should arrange for others to convert the foreign currency in their charity funds (e.g., using a bank) rather than converting it themselves, because people might think that they gave themselves a more favorable exchange rate.10
  • In a similar vein, one who manages a charity fund must not show partiality to family members or friends when distributing charity.11

Mar'it Ayin

One may not perform certain actions that appear to be forbidden, even if one is in fact doing them in a permissible way. This is called mar'it ayin (lit., "what appears to the eye"). This is only forbidden if the activity is something that is usually forbidden but is now being done in a permissible way. If, however, the activity is usually permissible, one need not be concerned that people will suspect him of doing it in a forbidden way.12

Several examples of this are as follows.

When it comes to allowing non-Jews to do paid work for one on Shabbat:

  • One may not allow a non-Jewish workman to do work (forbidden for a Jew to do on Shabbat) in his house on Shabbat even if the workman is being paid by the job and was not instructed to do the work on Shabbat.13 (Technically, this would be permitted, but since people may think that it was arranged in a forbidden way, it may not be done.)
  • One may not allow workers to build one's home on ShabbatOne may not allow workers to build one's home on Shabbat (even if he's currently not occupying it). This is true even when they are contracted by the job and were not instructed to do the work specifically on Shabbat. The reason for this is that people may not be aware of the contractual agreement.14 The law of mar'it ayin differs when it comes to a house owned by a Jew that is being built outside of the city. If no Jew lives in that area and the work has been contracted by the job, building work may be performed by non-Jewish workers on Shabbat.15

When it comes to eating and drinking:

  • One may not drink fish blood unless there are scales floating in it. Otherwise, people may think that the drinker is drinking the (forbidden) blood of animals.16
  • Rabbi Moshe Isserlis writes17 that if one cooks (and eats) meat in almond milk, one should place almonds in area so that no one should think that he is transgressing the prohibition of cooking and eating meat and milk together.18

Despite this, Rabbi Ovadiah Yosef writes19 that a restaurant may serve non-dairy creamer with the coffee served at meat meals. This because nowadays these creamers (and non-dairy milk) are common, and because the person is not actually eating it with the meat.

In fact, I heard from Rabbi Avrohom Tzvi Wozner of Monsey, New York, that nowadays any non-dairy milk or cheeses which are common may be used with meat. Due to their prevalence, people will not suspect that they are actually dairy.

  • Rabbi Moshe Feinstein20 ruled that one may not eat in a non-kosher restaurant even if he can ensure that all of the food being served to him is kosher.

Other prohibitions:

  • Some say that one should not give one's clothes to the dry-cleaners during the Nine Days (when it is forbidden to wash clothes) even if one tells them to not wash them until after the Nine Days are over. Others permit this.21
  • One may not hang wet clothes out to dry on Shabbat as it may appear that he washed them on Shabbat.22

All these activities may not be performed even in a private areaAll these activities may not be performed even in a private area (in halachic lingo, "in a room within a room") that is free of bystanders.23 If, however, the activity can be mistaken for a transgression of merely a Rabbinic prohibition, as opposed to a violation of Torah law, it may not be performed publicly, but may be performed in private.24

Rabbi Moshe Feinstein writes25 that the laws of mar'it ayin cannot necessarily be extrapolated from one case to another. This is because some activities are more prone to be mistaken for forbidden activities then others. For this reason:

  • A married women may wear a wig, and we are not concerned that others will suspect that she is not covering her hair at all. Since in most cases one can differentiate between a wig and natural hair, the Sages did not apply the rules of mar'it ayin to this case, despite the fact that sometimes onlookers may make this mistake. (See The Meaning of Hair Covering for more on why married women cover their hair, and here for the Lubavitcher Rebbe's perspective on this issue.)
  • One who follows the opinion that it is permissible to shave with an electric shaver may do so despite the fact that some may think that he shaves with an actual razor. Since it is generally easy to distinguish the difference between electric shavers and razors in that the shavers do not cut as close as the regular razors, the Sages did not enact any decree against this.